tag:blogger.com,1999:blog-75060566140654902082024-03-18T03:04:18.166+00:00Geology in the West CountryTalks, field trips and events organised by west country geological organisations are publicised on this blog. Discussion about geological topics is encouraged. Anything of general geological interest is included.Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.comBlogger1869125tag:blogger.com,1999:blog-7506056614065490208.post-33308083238346707732024-03-16T14:27:00.000+00:002024-03-16T14:27:40.089+00:00Anthropocene - the Ongoing Story<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> Anthropocene - the Ongoing Story</span></h1><div><span style="font-family: verdana;">The Anthropocene Working Group recently decided not to recognise the existence of the Anthropocene - much to the disgust of some members of the group - see <a href="https://theconversation.com/what-the-anthropocenes-critics-overlook-and-why-it-really-should-be-a-new-geological-epoch-225493?utm_medium=email&utm_campaign=Latest%20from%20The%20Conversation%20for%20March%2013%202024%20-%202905529516&utm_content=Latest%20from%20The%20Conversation%20for%20March%2013%202024%20-%202905529516+CID_d0331f3e699fbbe78e86fa0b4a917099&utm_source=campaign_monitor_uk&utm_term=What%20the%20Anthropocenes%20critics%20overlook%20%20and%20why%20it%20really%20should%20be%20a%20new%20geological%20epoch" target="_blank">HERE</a>.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">If the Anthropocene had been recognised it would have marked the end of the Holocene, the current geological epoch, which began 11,700 years ago at the end of the Younger Dryas. There has been much discussion about when the putative Anthropocene would be deemed to start. I had a strange wish to straddle two Geological Epochs! </span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">The wish for the new epoch has a great deal to do with environmental concerns. Perhaps it should be considered an Event rather than Epoch, similar to the Great Oxygenation Event of the Proterozoic, the Snowball Earth Events and the Palaeocene-Eocene Thermal Maximum. </span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">And as <a href="https://earthlogs.org/2024/03/08/the-anthropocene-epoch-bites-the-dust/" target="_blank">THIS ARTICLE</a> suggests, global warming has been caused by a small number of people rather than humanity as a whole and would be better named Plutocracene!</span></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-20096636245409656102024-03-05T10:30:00.003+00:002024-03-05T12:34:40.015+00:00Earliest Forest in the World in Devon and Somerset<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> Earliest Forest in the World in Devon and Somerset</span></h1><div><span style="font-family: verdana;">A correspondent sent me the link to <a href="https://www.livescience.com/planet-earth/plants/fossilized-forest-unearthed-in-the-uk-is-the-oldest-ever-found-at-390-million-years-old" target="_blank">THIS ARTICLE</a>, for which I am very grateful. The article is based on <a href="https://www.lyellcollection.org/doi/epdf/10.1144/jgs2023-204" target="_blank">THIS PAPER</a>. The papers concern newly discovered fossil trees found in Middle Devonian sandstones in the Hangman Sandstone Formation which is of Eifelian age (393 - 387 million years).</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">Not only were fossilised trees found but also forests. The trees are of an extinct species related to ferns and horsetails - the cladoxylopsids, which look rather like palm trees - long stem (2 - 4m) with "leaves" like palm fronds at the top. (Here "leaves" means lots of twiglets.)</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">There are older trees to be found but this is the oldest forest. And it marks the time when vegetation had a significant impact on sedimentation, changing the way the non-marine surface of the earth looked. </span></div><div><span style="font-family: verdana;"><br /></span></div><div style="text-align: center;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhiyWmZSBFNy55FW_9349fYu4vBNl8XQMXPrKM_YuW-aHTurEk44WJRZzSQGx9FXQBVhGKFYv92Wc8rhGfuvisgBV6SfSK2hw5aCJXCWhk7Y93Q3C49OYBTCkSQpv4o6jtNHFCxhsqfao6mtlUw97YAj38AUCl0RRu7Ae__yJIWeA8qOc9YtKzVwMy4R1M/s896/forest%201.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="896" data-original-width="767" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhiyWmZSBFNy55FW_9349fYu4vBNl8XQMXPrKM_YuW-aHTurEk44WJRZzSQGx9FXQBVhGKFYv92Wc8rhGfuvisgBV6SfSK2hw5aCJXCWhk7Y93Q3C49OYBTCkSQpv4o6jtNHFCxhsqfao6mtlUw97YAj38AUCl0RRu7Ae__yJIWeA8qOc9YtKzVwMy4R1M/w548-h640/forest%201.jpg" width="548" /></a></div><span style="color: #0b5394; font-family: verdana;"><div style="text-align: center;"><span style="color: #0b5394; font-family: verdana;"><br /></span></div><div style="text-align: center;">The Hangman Sandstone Formation</div><div style="text-align: center;"><br /></div><div style="text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEguH50KQDoYhxCpeg0Hb1pjVmFMOWpSKQzcKe6Isf2vjYIyIia8-88eI_feZSwlBzOnK-Yt7hwP8PNuwqZLHsxjsQ7tBDm-zcnj0vBdeJVg4yRmDjzvh0sW-ZCz5-WdWUl2yanJjhrGG0tvfT_zllLR6sgh_aKNNXgqQ9WdUn_OtlecGg4UAz2ri80Xka8/s1073/forest%202.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1073" data-original-width="763" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEguH50KQDoYhxCpeg0Hb1pjVmFMOWpSKQzcKe6Isf2vjYIyIia8-88eI_feZSwlBzOnK-Yt7hwP8PNuwqZLHsxjsQ7tBDm-zcnj0vBdeJVg4yRmDjzvh0sW-ZCz5-WdWUl2yanJjhrGG0tvfT_zllLR6sgh_aKNNXgqQ9WdUn_OtlecGg4UAz2ri80Xka8/w456-h640/forest%202.jpg" width="456" /></a></div><div style="text-align: center;"><span style="color: #0b5394; font-family: verdana;"><br /></span></div>The tree trunks are preserved mostly as impressions. The most abundant forms show a three-dimensional surface, consisting of longitudinal strips of slightly raised smooth matrix alternating with slightly lower relief strips in which short transverse depressions are closely arranged (A - D). (See pages 12 and 13 of the academic paper)</span></div><div style="text-align: center;"><span style="color: #0b5394; font-family: verdana;"><br /></span></div><div style="text-align: center;"><br /></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-60839295564416019972024-03-02T14:41:00.001+00:002024-03-02T14:41:20.116+00:00Down to Earth Extra March 2024<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> Down to Earth Extra March 2024</span></h1><div><span style="font-family: verdana;">The March 2024 edition of Down to Earth Extra has been published. You can download it <a href="https://app.box.com/s/um0hs8wskn9onbmxnl2nvzkknww3hu7x" target="_blank">HERE</a> or you can read it below.</span></div><div style="text-align: center;"><br /></div><p><iframe allowfullscreen="" frameborder="0" height="900" msallowfullscreen="" src="https://app.box.com/embed/s/wz2sn8se2d8zoqcrtj1reldtzfq8thhj?sortColumn=date" webkitallowfullscreen="" width="666"></iframe></p>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-14102029785881461902024-02-24T12:41:00.002+00:002024-02-24T15:17:23.832+00:00Predicting Volcanism in Iceland<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> Predicting Volcanism in Iceland</span></h1><div><span style="font-family: verdana;">It seems appropriate that the people in charge of predicting eruptions in Iceland work in the Meteorological Office. In Iceland, volcanism is like the weather, there is a lot of it and you can't prevent it but you can give forecasts which are very useful.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;"><a href="https://www.quantamagazine.org/inside-scientists-life-saving-prediction-of-the-iceland-eruption-20240220/?mc_cid=c9f63b665b&mc_eid=fb91382f4c" target="_blank">THIS ARTICLE</a> in Quanta Magazine is an interesting review of what has happened recently on, and in, the Reykjanes Peninsula of south west Iceland. It seems that there may be several centuries of volcanism to look forward to in the area.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">What is evident is that what could have been a deadly catastrophe became a well controlled emergency. - Small eruption in Iceland, nobody dead.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">The article is well written so I will not attempt to review the review but would urge you to read it.</span></div><div><span style="font-family: verdana;"><br /></span></div><div style="text-align: center;"><div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='666' height='555' src='https://www.blogger.com/video.g?token=AD6v5dzwsZKL3IdEaxv5x6N-qWFiYJHhLdqrT59E-abBTDIhbGgk883AvsXWAi-1DCoZ__5nXLu4lblC5wXJRg-hpA' class='b-hbp-video b-uploaded' frameborder='0'></iframe></div><br /><span style="color: #0b5394; font-family: verdana;"><i><div>A 3-kilometer-long fissure opened up and sent a river of lava flowing over a road in southwest Iceland on February 8, 2024 — right on schedule.</div><div style="text-align: right;">Hilmar Bragi Bárðarson</div></i></span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;"><br /></span></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-53767482166114766832024-02-10T12:46:00.000+00:002024-02-10T12:46:01.541+00:00Pterosaur from Skye<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> Pterosaur from Skye</span></h1><div><span style="font-family: verdana;">There has been a lot lately in the media about a pterosaur from Skye. It is based on research, much of which was done at Bristol University. The main academic paper can be seen <a href="https://www.tandfonline.com/doi/full/10.1080/02724634.2023.2298741" target="_blank">HERE</a>, the Bristol researcher writes about it <a href="https://theconversation.com/newly-identified-prehistoric-pterosaur-will-help-us-understand-evolution-of-flying-reptiles-222632?utm_medium=email&utm_campaign=Latest%20from%20The%20Conversation%20for%20February%206%202024%20-%202870329126&utm_content=Latest%20from%20The%20Conversation%20for%20February%206%202024%20-%202870329126+CID_c2214f96b62a701a55acbda85a1aac13&utm_source=campaign_monitor_uk&utm_term=Newly%20identified%20prehistoric%20pterosaur%20will%20help%20us%20understand%20evolution%20of%20flying%20reptiles" target="_blank">HERE</a> and the BBC writes about it <a href="https://www.bbc.co.uk/news/science-environment-68207021" target="_blank">HERE</a>.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">The fossil in question was found in 2006 at the location shown on the map below.</span></div><div><span style="font-family: verdana;"><br /></span></div><div style="text-align: center;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgw-9CjtZYhQca6Wut-xmS6BhntK3VvMtCR7dliHt8sUP8RZ-intUBKYaDZLrKyzHlBeDFHO9MYVmJmqaBkC_L0mcJ0-2UhcxbXoXRcbf2WgGZ1c5icQQgYYQKQHs7tF01vXPcr31tonBRghPDGuTo8PcaCx-QN4pzHVEiYH1TVFYRmd-4r8Z6UTKzARDQ/s1087/pterosaur%201.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1087" data-original-width="1041" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgw-9CjtZYhQca6Wut-xmS6BhntK3VvMtCR7dliHt8sUP8RZ-intUBKYaDZLrKyzHlBeDFHO9MYVmJmqaBkC_L0mcJ0-2UhcxbXoXRcbf2WgGZ1c5icQQgYYQKQHs7tF01vXPcr31tonBRghPDGuTo8PcaCx-QN4pzHVEiYH1TVFYRmd-4r8Z6UTKzARDQ/w612-h640/pterosaur%201.jpg" width="612" /></a></div><br /><div style="text-align: left;"><span style="font-family: verdana;">The fossil took much preparation and was examined in Bristol University's CT scanner. The bones are thin and fragile and the rock matrix hard so getting to the stage of examining the bones took a long time. Read the academic paper to get a flavour of all the work involved.</span></div><div style="text-align: left;"><span style="font-family: verdana;"><br /></span></div><div style="text-align: left;"><span style="font-family: verdana;">The main interest of the fossil is that it is more than an isolated bone and that it comes from a geologic period where a lot was happening to pterosaurs but which is poorly represented in the geologic column.</span></div><div style="text-align: left;"><span style="font-family: verdana;"><br /></span></div><div style="text-align: left;"><span style="font-family: verdana;">Be amazed at all the measurements the researchers have made. They have decided that it is a new species - <i>Ceoptera evansae.</i></span></div><div style="text-align: left;"><span style="font-family: verdana;"><i><br /></i></span></div><div style="text-align: center;"><span style="font-family: verdana;"><div class="separator" style="clear: both; text-align: center;"><a href="https://www.tandfonline.com/cms/asset/6dcee583-dcf1-4082-9365-dc36af0a3510/ujvp_a_2298741_f0012_oc.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="444" data-original-width="800" height="355" src="https://www.tandfonline.com/cms/asset/6dcee583-dcf1-4082-9365-dc36af0a3510/ujvp_a_2298741_f0012_oc.jpg" width="640" /></a></div><div style="text-align: center;"><span style="font-family: verdana;"><br /></span></div><span style="color: #0b5394;"> Life reconstruction of Ceoptera evansae. Image copyright Mark Witton.</span><br /><i><br /></i></span></div></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-37241601397570083452024-02-01T15:21:00.000+00:002024-02-01T15:21:19.837+00:00Looking at Early Life<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> Looking at Early Life</span></h1><p><br /></p><div class="separator" style="clear: both; text-align: center;"><a href="https://images.newscientist.com/wp-content/uploads/2024/01/19132231/SEI_187754116.jpg?width=900" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="514" data-original-width="800" height="411" src="https://images.newscientist.com/wp-content/uploads/2024/01/19132231/SEI_187754116.jpg?width=900" width="640" /></a></div><p style="text-align: center;"><span style="color: #0b5394; font-family: verdana;">A sample of chert rock containing what may be the remains of microorganisms that lived 3.4 billion years ago. </span><span style="color: #0b5394; font-family: verdana;">Dr. Manuel Reinhardt</span></p><p style="--tw-border-spacing-x: 0; --tw-border-spacing-y: 0; --tw-ring-color: rgba(69,89,164,.5); --tw-ring-offset-color: #fff; --tw-ring-offset-shadow: 0 0 transparent; --tw-ring-offset-width: 0px; --tw-ring-shadow: 0 0 transparent; --tw-rotate: 0; --tw-scale-x: 1; --tw-scale-y: 1; --tw-scroll-snap-strictness: proximity; --tw-shadow-colored: 0 0 transparent; --tw-shadow: 0 0 transparent; --tw-skew-x: 0; --tw-skew-y: 0; --tw-translate-x: 0; --tw-translate-y: 0; border: 0px solid rgb(217, 217, 227); box-sizing: border-box; color: #374151; margin: 0px 0px 1.25em; white-space-collapse: preserve;"><span style="font-family: verdana;">Around 3.4 billion years ago, Earth hosted diverse communities of life, as evidenced by exceptionally preserved remains revealing a microorganism ecosystem with various sustenance methods. The complexity of this ancient ecosystem suggests that life had likely existed for hundreds of millions of years, starting early in Earth's history.</span></p><p style="--tw-border-spacing-x: 0; --tw-border-spacing-y: 0; --tw-ring-color: rgba(69,89,164,.5); --tw-ring-offset-color: #fff; --tw-ring-offset-shadow: 0 0 transparent; --tw-ring-offset-width: 0px; --tw-ring-shadow: 0 0 transparent; --tw-rotate: 0; --tw-scale-x: 1; --tw-scale-y: 1; --tw-scroll-snap-strictness: proximity; --tw-shadow-colored: 0 0 transparent; --tw-shadow: 0 0 transparent; --tw-skew-x: 0; --tw-skew-y: 0; --tw-translate-x: 0; --tw-translate-y: 0; border: 0px solid rgb(217, 217, 227); box-sizing: border-box; color: #374151; margin: 1.25em 0px; white-space-collapse: preserve;"><span style="font-family: verdana;"><a href="https://www.sciencedirect.com/science/article/pii/S0301926824000020" target="_blank">THIS ACADEMIC PAPER</a>, focused on rocks from the Buck Reef Chert in South Africa, dating back 3.42 billion years. These rocks are believed to be remnants of the shallow seas around a chain of volcanic islands. The layers of rock contain microscopic carbon-based matter, likely the remains of microorganisms from the ancient seas.</span></p><p style="--tw-border-spacing-x: 0; --tw-border-spacing-y: 0; --tw-ring-color: rgba(69,89,164,.5); --tw-ring-offset-color: #fff; --tw-ring-offset-shadow: 0 0 transparent; --tw-ring-offset-width: 0px; --tw-ring-shadow: 0 0 transparent; --tw-rotate: 0; --tw-scale-x: 1; --tw-scale-y: 1; --tw-scroll-snap-strictness: proximity; --tw-shadow-colored: 0 0 transparent; --tw-shadow: 0 0 transparent; --tw-skew-x: 0; --tw-skew-y: 0; --tw-translate-x: 0; --tw-translate-y: 0; border: 0px solid rgb(217, 217, 227); box-sizing: border-box; color: #374151; margin: 1.25em 0px; white-space-collapse: preserve;"><span style="font-family: verdana;">Analyzing the chemical makeup of these remains, the researchers honed in on carbon isotopes, specifically carbon-12 and carbon-13. Living organisms prefer carbon-12, and the ratio between the two isotopes provides insights into an organism's metabolism. The material showed a carbon signature consistent with photosynthesis, indicating the presence of vast quantities of photosynthetic microbes near the sea surface billions of years ago.</span></p><p style="--tw-border-spacing-x: 0; --tw-border-spacing-y: 0; --tw-ring-color: rgba(69,89,164,.5); --tw-ring-offset-color: #fff; --tw-ring-offset-shadow: 0 0 transparent; --tw-ring-offset-width: 0px; --tw-ring-shadow: 0 0 transparent; --tw-rotate: 0; --tw-scale-x: 1; --tw-scale-y: 1; --tw-scroll-snap-strictness: proximity; --tw-shadow-colored: 0 0 transparent; --tw-shadow: 0 0 transparent; --tw-skew-x: 0; --tw-skew-y: 0; --tw-translate-x: 0; --tw-translate-y: 0; border: 0px solid rgb(217, 217, 227); box-sizing: border-box; color: #374151; margin: 1.25em 0px; white-space-collapse: preserve;"><span style="font-family: verdana;">However, some blobs exhibited lower levels of carbon-12, suggesting a different metabolic process. The authors propose that these microbes were likely feeding on acetyl coenzyme A. Other blobs with even lower carbon-12 levels indicated microbes producing methane or acetate as waste products, which were then potentially consumed by other microbes.</span></p><p style="--tw-border-spacing-x: 0; --tw-border-spacing-y: 0; --tw-ring-color: rgba(69,89,164,.5); --tw-ring-offset-color: #fff; --tw-ring-offset-shadow: 0 0 transparent; --tw-ring-offset-width: 0px; --tw-ring-shadow: 0 0 transparent; --tw-rotate: 0; --tw-scale-x: 1; --tw-scale-y: 1; --tw-scroll-snap-strictness: proximity; --tw-shadow-colored: 0 0 transparent; --tw-shadow: 0 0 transparent; --tw-skew-x: 0; --tw-skew-y: 0; --tw-translate-x: 0; --tw-translate-y: 0; border: 0px solid rgb(217, 217, 227); box-sizing: border-box; color: #374151; margin: 1.25em 0px; white-space-collapse: preserve;"><span style="font-family: verdana;">The distribution of these microorganisms is challenging to determine, but it is suggested that photosynthetic ones lived near the water's surface, while others might have resided in seabed sediments. It seems early life functioned similarly to present-day life.</span></p><p style="--tw-border-spacing-x: 0; --tw-border-spacing-y: 0; --tw-ring-color: rgba(69,89,164,.5); --tw-ring-offset-color: #fff; --tw-ring-offset-shadow: 0 0 transparent; --tw-ring-offset-width: 0px; --tw-ring-shadow: 0 0 transparent; --tw-rotate: 0; --tw-scale-x: 1; --tw-scale-y: 1; --tw-scroll-snap-strictness: proximity; --tw-shadow-colored: 0 0 transparent; --tw-shadow: 0 0 transparent; --tw-skew-x: 0; --tw-skew-y: 0; --tw-translate-x: 0; --tw-translate-y: 0; border: 0px solid rgb(217, 217, 227); box-sizing: border-box; color: #374151; margin: 1.25em 0px 0px; white-space-collapse: preserve;"><span style="font-family: verdana;">The research also contributes to the growing evidence supporting an early origin of life on Earth, challenging previous fossil record interpretations. While widely accepted evidence for life is around 3.5 billion years old, older fossils from 3.7 billion years ago or earlier have been reported. However, the difficulty in detecting well-preserved rocks from that era makes it challenging to uncover the earliest history of life. But some suggest that life may have emerged during the Hadean eon, around 4.2 to 4.1 billion years ago.</span></p><p style="--tw-border-spacing-x: 0; --tw-border-spacing-y: 0; --tw-ring-color: rgba(69,89,164,.5); --tw-ring-offset-color: #fff; --tw-ring-offset-shadow: 0 0 transparent; --tw-ring-offset-width: 0px; --tw-ring-shadow: 0 0 transparent; --tw-rotate: 0; --tw-scale-x: 1; --tw-scale-y: 1; --tw-scroll-snap-strictness: proximity; --tw-shadow-colored: 0 0 transparent; --tw-shadow: 0 0 transparent; --tw-skew-x: 0; --tw-skew-y: 0; --tw-translate-x: 0; --tw-translate-y: 0; border: 0px solid rgb(217, 217, 227); box-sizing: border-box; color: #374151; margin: 1.25em 0px 0px; white-space-collapse: preserve;"><span style="font-family: verdana;"><br /></span></p><p style="--tw-border-spacing-x: 0; --tw-border-spacing-y: 0; --tw-ring-color: rgba(69,89,164,.5); --tw-ring-offset-color: #fff; --tw-ring-offset-shadow: 0 0 transparent; --tw-ring-offset-width: 0px; --tw-ring-shadow: 0 0 transparent; --tw-rotate: 0; --tw-scale-x: 1; --tw-scale-y: 1; --tw-scroll-snap-strictness: proximity; --tw-shadow-colored: 0 0 transparent; --tw-shadow: 0 0 transparent; --tw-skew-x: 0; --tw-skew-y: 0; --tw-translate-x: 0; --tw-translate-y: 0; border: 0px solid rgb(217, 217, 227); box-sizing: border-box; margin: 1.25em 0px 0px; white-space-collapse: preserve;"><span style="color: red; font-family: verdana;"><i>Many readers of this blog will be amazed at the quality of this article. I did not write it! It was written by <a href="http://ChatGPT.">ChatGPT.</a> I copied <a href="https://www.newscientist.com/article/2413292-traces-of-ancient-life-reveal-a-3-4-billion-year-old-ecosystem/" target="_blank">THIS ARTICLE</a> from New Scientist and asked ChatGPT to summarise it in about 400 words, and it did it in 359. I modified the output slightly. Be aware that I will not be doing this on a regular basis but did it as an exercise to see the quality of the output - and I am impressed. Back to the less impressive me next time!</i></span></p>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-76664375663344996752024-01-31T16:37:00.001+00:002024-01-31T16:37:14.347+00:00Earth Heritage, Issue 60, Winter 2024<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> Earth Heritage, Issue 60, Winter 2024</span></h1><div><span style="font-family: verdana;">The Winter 2024 issue of Earth Heritage is available for download on <a href="https://www.earthheritage.org.uk/downloads/" target="_blank">THIS PAGE</a>.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">Or you can read it below.</span></div><div><span style="font-family: verdana;"><br /></span></div><div style="text-align: center;"><span style="font-family: verdana;"><br /></span><iframe src="https://app.box.com/embed/s/p1dmccvap05kdr7ds58ztmqa1mgigemr?sortColumn=date" width="666" height="900" frameborder="0" allowfullscreen webkitallowfullscreen msallowfullscreen></iframe></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-68723535806322839212024-01-27T15:47:00.001+00:002024-01-27T15:47:18.263+00:00New Dinosaur Species were Evolving when the Asteroid Struck!<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> New Dinosaur Species were Evolving when the Asteroid Struck!</span></h1><div><span style="font-family: verdana;">Many palaeontologists believe that dinosaurs were on the way out when the asteroid struck at the end of the Cretaceous and the impact was the straw which broke the camels back. (Apologies for the metaphor.)</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">But <a href="https://theconversation.com/a-newly-identified-hell-chicken-species-suggests-dinosaurs-werent-sliding-toward-extinction-before-the-fateful-asteroid-hit-221482?utm_medium=email&utm_campaign=Latest%20from%20The%20Conversation%20for%20January%2026%202024%20-%202859529010&utm_content=Latest%20from%20The%20Conversation%20for%20January%2026%202024%20-%202859529010+CID_5331859767d4edd5e40c6c64c9cfcdf3&utm_source=campaign_monitor_uk&utm_term=A%20newly%20identified%20Hell%20chicken%20species%20suggests%20dinosaurs%20werent%20sliding%20toward%20extinction%20before%20the%20fateful%20asteroid%20hit" target="_blank">THIS ARTICLE</a> contends that new species were continuing to evolve. The perceived decrease in diversity is caused by the difficulty in identifying new species. </span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;"> They illustrate this by describing how museum specimens described as being a juvenile specimen of a recognised species was actually a completely new species which evolved at the relevant time.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">And they do this by looking at the spacing of growth rings in the animals bones. If it was a juvenile the rings would be wide - rapid growth. But this animal has closely spaced growth rings indicating it was an adult. </span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">It had been classified as a juvenile "chicken from hell" <span style="color: #0b5394; font-style: italic;">Eoneophron anzu</span><span>. (I think that is the official name of the larger beastie - the article is not very clear on this.) It has been given the name <span style="color: #0b5394;"><i>Eoneophron infernalis. </i></span></span></span></div><div><span style="font-family: verdana;"><span><span style="color: #0b5394;"><i><br /></i></span></span></span></div><div><span style="font-family: verdana;"><span>So new species were evolving right up to the time of the impact.</span></span></div><div><span style="font-family: verdana;"><span><span style="color: #0b5394;"><i><br /></i></span></span></span></div><div style="text-align: center;"><span style="font-family: verdana;"><span><span style="color: #0b5394;"><div class="separator" style="clear: both; text-align: center;"><a href="https://images.theconversation.com/files/570996/original/file-20240123-17-53v1e0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=572&fit=crop&dpr=1" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="572" data-original-width="754" height="486" src="https://images.theconversation.com/files/570996/original/file-20240123-17-53v1e0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=572&fit=crop&dpr=1" width="640" /></a></div><br />Teal markers point to lines of arrested growth on the cross-section of fossilized bone. Toward the outside of the bone, the lines are much closer together, reflecting less growth per year. Researchers counted exactly six lines, meaning this animal was between 6 and 7 years old when it died. Holly Woodward</span></span></span></div><div style="text-align: center;"><span style="font-family: verdana;"><span><span style="color: #0b5394;"><br /></span></span></span></div><div style="text-align: center;"><span style="font-family: verdana;"><span><span style="color: #0b5394;"><br /></span></span></span></div><div><span style="font-family: verdana;"><span><span style="color: #0b5394;"><i><br /></i></span></span></span></div><div><span style="font-family: verdana;"><span>And here is a picture of the animal itself.</span></span></div><div><span style="font-family: verdana;"><span><br /></span></span></div><div style="text-align: center;"><span style="font-family: verdana;"><div class="separator" style="clear: both; text-align: center;"><a href="https://images.theconversation.com/files/570405/original/file-20240119-25-cv46uw.jpg?ixlib=rb-1.1.0&rect=386%2C718%2C3592%2C2613&q=45&auto=format&w=926&fit=clip" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="582" data-original-width="800" height="466" src="https://images.theconversation.com/files/570405/original/file-20240119-25-cv46uw.jpg?ixlib=rb-1.1.0&rect=386%2C718%2C3592%2C2613&q=45&auto=format&w=926&fit=clip" width="640" /></a></div><br /><span style="color: #0b5394;">Birdlike dinosaur Eoneophron infernalis was about the size of an adult human. Zubin Erik Dutta</span></span></div><div><span style="font-family: verdana;"><span><span style="color: #0b5394;"><i><br /></i></span></span></span></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-86966919371786494182024-01-20T12:19:00.000+00:002024-01-20T12:19:36.532+00:00I Won't Live Forever Because of the Dinosaurs!<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> I Won't Live Forever Because of the Dinosaurs!</span></h1><div><span style="font-family: verdana;">Mammals were at the bottom of the food chain when dinosaurs were the top predators and therefore to survive mammals became small, nocturnal and short-lived. They had to reproduce rapidly and did not need processes and genes related to long life such as repair and regeneration.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">The same cannot be said for reptiles, amphibians and fish. They die from being eaten, not from old age! Many of these continue to reproduce throughout their lives.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">I read about this fascinating subject in <a href="https://theconversation.com/could-dinosaurs-be-the-reason-humans-cant-live-for-200-years-219435" target="_blank">THIS ARTICLE</a>. </span></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-68299623390455227372024-01-06T15:07:00.002+00:002024-01-06T15:07:50.005+00:00Dolomite - Solved?<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;">Dolomite - Solved? </span></h1><div><span style="font-family: verdana;">Many old rocks are dolomite, younger ones are seldom dolomite - why? </span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">There has been some activity in the dolomite field which shows that you can grow dolomite in the laboratory relatively quickly by repeatedly washing the growing crystal. </span></div><div><span style="font-family: verdana;"><i><span style="color: #0b5394;"><br /></span></i></span></div><div><span style="font-family: verdana;"><i><span style="color: #0b5394;">(Dolomite crystals have layers of calcium, carbonate, magnesium, endlessly repeated. In the rocks there is no magnesium in the calcium layers and no calcium in the magnesium layers. Up to now this was impossible to replicate in the laboratory.)</span></i></span></div><div><span style="font-family: verdana;"><i><span style="color: #0b5394;"><br /></span></i></span></div><div><span style="font-family: verdana;"><span>The original paper which tells how to make dolomite is <a href="https://www.researchgate.net/publication/375889658_A_fluctuating_solution_to_the_dolomite_problem" target="_blank">HERE</a>. And "popular" readings of the paper are <a href="https://www.forbes.com/sites/davidbressan/2023/11/27/scientists-solve-200-year-old-dolomite-problem/" target="_blank">HERE</a> and <a href="https://news.umich.edu/200-year-old-geology-mystery-resolved/" target="_blank">HERE</a> and lots of other places.</span></span></div><div><span style="font-family: verdana;"><span><br /></span></span></div><div><span style="font-family: verdana;"><span>This is very interesting but I am not sure that it tells us why dolomite is not being made in nature now.</span></span></div><div><span style="font-family: verdana;"><span><br /></span></span></div><div><span style="font-family: verdana;"><span>Another annoyance is that the popular papers are obvious copies of each other - they all tell us that the White Cliffs of Dover are dolomite. At least that is not in the original.</span></span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;"><br /></span></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-15142605152862455342024-01-06T14:34:00.002+00:002024-01-06T14:34:54.225+00:00Down to Earth Extra January 2024<h1 style="text-align: left;"><span style="color: #990000;"><span style="font-family: verdana; font-size: x-large;"> Down to Earth Extra January 2024</span></span></h1><h1><span style="font-family: verdana; font-size: small; font-weight: normal;">The December 2023 edition of Down to Earth Extra has been published. You can download it <a href="https://app.box.com/s/om52xsevmof0txhcu601qb4lxltopzlh" style="text-decoration-line: none;" target="_blank">HERE</a> or you can read it below.</span></h1><div style="text-align: center;"><br /></div><h1><span style="color: #990000;"><iframe allowfullscreen="" frameborder="0" height="900" msallowfullscreen="" src="https://app.box.com/embed/s/om52xsevmof0txhcu601qb4lxltopzlh?sortColumn=date" webkitallowfullscreen="" width="660"></iframe></span></h1>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-9422222119678377402023-12-16T11:45:00.002+00:002023-12-16T11:45:30.723+00:00The Danger of Melting Permafrost<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> The Danger of Melting Permafrost</span></h1><div><span style="font-family: verdana;"><a href="https://www.sciencealert.com/arctic-permafrost-hides-migrating-methane-that-could-skyrocket-emissions?utm_source=ScienceAlert+-+Daily+Email+Updates&utm_campaign=9c5fa0e437-RSS_EMAIL_CAMPAIGN&utm_medium=email&utm_term=0_fe5632fb09-9c5fa0e437-365599033" target="_blank">THIS ARTICLE</a> tells of the dangers of permafrost melting - release of methane. It is based on <a href="https://www.frontiersin.org/articles/10.3389/feart.2023.1277027/full" target="_blank">THIS ACADEMIC PAPER</a>. (The article has less than 650 words, the paper has over 14,000 so the paper is more nuanced than the article.) </span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">It seems that permafrost acts as a "cap rock" for methane. The research was done in Svalbard where there has been a long history of hydrocarbon exploration. </span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">The methane has two sources - biogenic - recent sources - and thermogenic - geologic timescales - and both sorts have been sealed from the atmosphere by permafrost.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">With global warming permafrost is becoming less permanent and methane is likely to escape into the atmosphere where it is a potent greenhouse gas. The amounts involved are unknown. </span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">Something else to worry about.</span></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-54635088800011400222023-12-09T11:23:00.001+00:002023-12-09T11:24:58.607+00:00Two New Nick Chidlaw Courses<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> Two New Nick Chidlaw Courses</span></h1><div><span style="font-family: verdana;">Nick Chidlaw wants to run two courses early next year. The format of the courses is that he sends enrolees a digital document for them to study for two weeks; then follows a week for people to ask Nick questions by email. </span><span style="font-family: verdana;">Then Nick sends everyone the most informative questions and answers.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">The courses are:-</span></div><div><span style="font-family: verdana;"><br /></span></div><div><div><span style="color: #0b5394; font-family: verdana;">A YOUNG OROGENIC BELT: COLLISION OF THE INDIAN TECTONIC PLATE WITH ASIA </span></div><div><span style="color: #0b5394; font-family: verdana;">Tutor: Dr Nick Chidlaw </span></div><div><span style="color: #0b5394; font-family: verdana;">Reading Period: Monday 15th – Sunday 28th January 2024 (2 weeks)</span></div><div><span style="color: #0b5394; font-family: verdana;">Dialogue Period: Monday 29th January – Sunday 4th February 2024 (1 week)</span></div><div><span style="color: #0b5394; font-family: verdana;">Tuition fee £33.00 per person.</span></div><div style="font-family: verdana;">----------------------------------------------------</div></div><div style="font-family: verdana;"><br /></div><div style="font-family: verdana;"><div><span style="color: #0b5394;">AN ANCIENT OROGENY: THE GRAMPIAN OROGENIC BELT, NORTHERN SCOTLAND</span></div><div><span style="color: #0b5394;">Tutor: Dr Nick Chidlaw</span></div><div><span style="color: #0b5394;">Reading Period: Monday 5th - Sunday 18th February 2024 (2 weeks)</span></div><div><span style="color: #0b5394;">Dialogue Period: Monday 19th – Sunday 25th February 2024 (1 week)</span></div><div><span style="color: #0b5394;">Tuition fee £33.00 per person.</span></div><div>--------------------------------------</div><div><span style="color: #0b5394;"><br /></span></div><div>In both cases the closing date for enrolment is Sunday 7th January.</div><div><br /></div><div>Nick has prepared a document which has all the details. You can get a copy <a href="https://app.box.com/s/0bs47zmx4965v265if5ah8yd9xl438d4" target="_blank">HERE</a>.</div><div><br /></div></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-62312959179197620562023-12-01T16:19:00.001+00:002023-12-01T16:19:47.332+00:00Down to Earth Extra December 2023<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> Down to Earth Extra December 2023</span></h1><div><span style="font-family: verdana;"><div><br /></div><div>The December 2023 edition of Down to Earth Extra has been published. You can download it <a href="https://app.box.com/s/b3jfyg7zasqvcdc8qrcr0t6jjqzkih3j" target="_blank">HERE</a> or you can read it below.</div><div><br /></div><div style="text-align: center;"><br /></div></span><iframe src="https://app.box.com/embed/s/b3jfyg7zasqvcdc8qrcr0t6jjqzkih3j?sortColumn=date" width="666" height="900" frameborder="0" allowfullscreen webkitallowfullscreen msallowfullscreen></iframe></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-31617515170901331102023-11-18T14:39:00.002+00:002023-11-18T14:39:30.082+00:00Iceland Volcano - A Good YouTube Channel<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> Iceland Volcano - A Good YouTube Channel</span></h1><div><span style="font-family: verdana;">The recent activity in Iceland has resulted in a multitude of stuff on YouTube. <a href="https://www.youtube.com/watch?v=bLKk7-sTYIg" target="_blank">THIS CHANNEL</a> is produced by a geology professor from Idaho who actually has done a lot of work on Icelandic volcanism. He produces a daily report which is very informative. Worth watching!</span></div><div><span style="font-family: verdana;"><br /></span></div><div style="text-align: center;"><span style="font-family: verdana;"><br /></span><iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen="" frameborder="0" height="375" src="https://www.youtube.com/embed/bLKk7-sTYIg" title="Latest Geologic Update Explores Possible Eruption Sites and Other Thoughts" width="666"></iframe></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-90207602626016997932023-11-11T15:54:00.004+00:002023-11-11T15:54:48.404+00:00Down to Earth Extra November 2023<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> Down to Earth Extra November 2023</span></h1><div><span style="font-family: verdana;">The November 2023 edition of Down to Earth Extra has been published. You can download it <a href="https://app.box.com/s/nx1lcxh28viwt8klmguzgeimphe3zbng" target="_blank">HERE</a> or you can read it below.</span></div><div><span style="font-family: verdana;"><br /></span></div><div style="text-align: center;"><br /></div><div><span style="color: #990000; font-family: verdana; font-size: x-large;"><br /></span><iframe allowfullscreen="" frameborder="0" height="900" msallowfullscreen="" src="https://app.box.com/embed/s/nx1lcxh28viwt8klmguzgeimphe3zbng?sortColumn=date" webkitallowfullscreen="" width="666"></iframe></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-5206331160661394252023-11-11T15:45:00.002+00:002023-11-11T15:45:27.288+00:00Icelandic Volcanoes<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> Icelandic Volcanoes</span></h1><div><span style="font-family: verdana;">Things seem to be happening fast in Iceland. A town (Grindavik) has been evacuated and an eruption is awaited. Unlike recent volcanic events in Iceland, this time there may be significant danger to infrastructure and lives.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">The following video explains what is going on.</span></div><div><span style="font-family: verdana;"><br /></span></div><div style="text-align: center;"><span style="font-family: verdana;"><br /></span><iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen="" frameborder="0" height="375" src="https://www.youtube.com/embed/Hx6kKec6kJo" title="Iceland Volcano Updates | An eruption could be imminent!" width="666"></iframe></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-47052606957325398632023-11-11T15:27:00.002+00:002023-11-11T15:36:52.687+00:00Has a New Continent Been Found?<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;">Has a New Continent Been Found? </span></h1><div><span style="font-family: verdana;">A correspondent sent me <a href="https://www.sciencealert.com/115-million-years-ago-an-entire-continent-vanished-now-weve-found-where-its-hiding?utm_source=ScienceAlert+-+Daily+Email+Updates&utm_campaign=1216b2b452-RSS_EMAIL_CAMPAIGN&utm_medium=email&utm_term=0_fe5632fb09-1216b2b452-366167241" target="_blank">THIS LINK</a>. It tells us about a bit of Australia which moved towards South-East Asia and got split up into fragments on its way. The article includes the following YouTube video. It shows what the authors think happened. All I can say is that it is mighty complicated! (<i>Click the full page symbol to make the video as large as possible. This might make it more comprehensible!</i>)</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;"><br /><div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen="" class="BLOG_video_class" height="266" src="https://www.youtube.com/embed/YeeUK9LNcVE" width="320" youtube-src-id="YeeUK9LNcVE"></iframe></div><br /></span></div><div><span style="font-family: verdana;">The amount of evidence collected must be huge. Trying to put it together to make a logical story is beyond my capabilities!</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">The intriguing thing is that it may explain the Wallace Line - the border between the flora and fauna of South-East Asia and Australia. But the time scales are surely different. The geology talks in terms of hundreds of millions of years, the flora and fauna would be a shorter time scale.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;"><br /></span></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-37635436558587846872023-11-11T15:00:00.003+00:002023-11-11T15:00:54.766+00:00How Do Moons Have Oceans?<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> How Do Moons Have Oceans?</span></h1><div><span style="font-family: verdana;">A correspondent emailed to tell me that <a href="https://www.quantamagazine.org/icy-oceans-exist-on-far-off-moons-why-arent-they-frozen-solid-20231102/?mc_cid=a5bcca8e45&mc_eid=10fbc362ce" target="_blank">THIS ARTICLE</a> was interesting and deserved to be in the blog. I concur!</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">The moons in question are some of those of Jupiter and Saturn. We don't know about those around Uranus and Neptune but stay tuned! </span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">The obvious one is Enceladus, the ice covered moon of Saturn. It has icy plumes erupting near its south pole. A fly through by the Cassini spacecraft found it to be water containing sodium chloride, quartz and hydrogen.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">Read the article to find the moons with oceans, but what interests me and the author is how does liquid water exist in what must be a very cold place. The answer seems to be tidal friction. </span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">In their orbits the moons are subject to gravitational forces from other moon and their parent planet, and these can vary enormously. Bits of the moons are moving against each other producing enough heat to keep their oceans liquid. The outermost parts are frozen, the interior is liquid.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">The presence of liquid water leads to speculation about the presence of life - read about it in the article.</span></div><div><span style="font-family: verdana;"><br /></span></div><div style="text-align: center;"><div class="separator" style="clear: both; text-align: center;"><a href="https://d2r55xnwy6nx47.cloudfront.net/uploads/2023/11/IcyOceanWorlds-NASA-JPL-Lede-scaled.webp" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="450" data-original-width="800" height="360" src="https://d2r55xnwy6nx47.cloudfront.net/uploads/2023/11/IcyOceanWorlds-NASA-JPL-Lede-scaled.webp" width="640" /></a></div><br /><span style="color: #0b5394; font-family: verdana;">Five images of Saturn’s moon Enceladus, seen in infrared light. Nestled beneath its icy shell is a global ocean — a sea that is erupting into space through fractures in the moon’s south pole, coloured red at bottom right.</span></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-59678596157402917852023-10-12T20:05:00.003+00:002023-10-12T20:05:40.724+00:00Two Indoor Courses from Nick Chidlaw<h1 style="text-align: center;"><span style="font-family: verdana; font-size: x-large;"> <span style="color: #990000;">Two Indoor Courses from Nick Chidlaw</span></span></h1><div><span style="font-family: verdana;"><span>Nick Chidlaw is running two courses this Autumn. Details are below.</span></span></div><div><span style="font-family: verdana;"><span><br /></span></span></div><div><span style="font-family: verdana;"><span>-------------------------------------</span></span></div><div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;">I am offering to run two 1-day indoor courses in November, if there is enough interest / availability for the courses to go ahead. These courses are repeats of ones I have run in the past, which pleasingly attracted many students; they are based on locations I where I have run field courses.</span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;"><br /></span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;">One of the courses focuses on the diverse sedimentary legacy deposited and landforms created during the 'Ice Age' within a part of the west of England. Many of these deposits are only occasionally exposed. The other course focuses on the concept of geological 'terranes', examining evidence for one along the Highland Border in Scotland. </span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;"><br /></span></div><div style="background-color: white;"><i><span style="color: #0b5394; font-family: verdana;">For both courses, no prior knowledge of geology or the study locations would be assumed. </span></i></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;"><br /></span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;">The courses may be attractive particularly to people who are not in a position to visit field locations e.g. insufficient time available because of family / work commitments, health difficulties, or who may be interested in the opportunity to study sediments that are no longer extant. <br /></span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;"><br /></span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;">Each course would comprise powerpoint-based lectures, together with examination of hand specimens of relevant mineral and rock types, and published geological maps of the field areas. The hand specimens have been collected by the tutor in the field areas described. </span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;"><br /></span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;">The venue is the Buckingham Room (single storey building by the car park) at The Chantry, 52 Castle Street Thornbury, Glos. BS35 1HB. See website <a data-saferedirecturl="https://www.google.com/url?q=http://www.thechantry.org.uk&source=gmail&ust=1697226605844000&usg=AOvVaw3FPekLGqvmMRKFLsVCZJzQ" href="http://www.thechantry.org.uk/" target="_blank">www.thechantry.org.uk</a> </span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;">for further details, including location map. On each course, attendees would bring their own packed lunch and other refreshments, or go into the town for lunch. </span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;"><br /></span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;">These two courses are <span style="background-color: yellow;">independent of one-another</span> - you can choose to do either, or both, according to your interests / availability. <b>The courses are £30.00 each</b>.</span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;"><br /></span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;">Viability will be a minimum of 10 enrolments / fee equivalent for each course. </span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;"><br /></span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;">If you / anybody else you know would like to attend these courses, do get in touch with me <a href="mailto:nickchidlaw@gmail.com" target="_blank">nickchidlaw@gmail.com</a>. </span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;"><br /></span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;">The <b>viability deadline</b> for both courses is <b style="background-color: yellow;">Saturday</b><span style="background-color: yellow;"> </span><b style="background-color: yellow;">4th November</b>. If either or both courses become viable on that date, <i>enrolments will be able to continue until 1 week before the dates the courses are to run. </i></span></div><div style="background-color: white;"><i><span style="color: #0b5394; font-family: verdana;"><br /></span></i></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;">If viability is not reached for either or both courses, fee received will be returned soon after to those who have sent them in. </span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;"><br /></span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;">Any queries, do get in touch. I look forward to hearing from you soon.</span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;"><br /></span></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;">Dr Nick Chidlaw</span></div></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;"><br /></span></div><div style="background-color: white;"><span style="font-family: verdana;">----------------------------------------</span></div><div style="background-color: white;"><span style="font-family: verdana;"><br /></span></div><div style="background-color: white;"><div><u><span style="color: #0b5394; font-family: verdana;"><i>Saturday 25th November</i></span></u></div><div><u><span style="color: #0b5394; font-family: verdana;"><i><br /></i></span></u></div><div><div><span style="color: #0b5394; font-family: verdana;"><i>'<b>The Ice Age in the Severn Vale and Cotswolds</b>'. 10.00 am - 5.00 pm </i></span></div><div><span style="color: #0b5394; font-family: verdana;"><i><br /></i></span></div><div><span style="color: #0b5394; font-family: verdana;"><i>The Quaternary period corresponds to the geological period we are currently living in; it includes what is popularly known as 'The Ice Age', together with the much milder climatic episode that began when the last glaciers in the British Isles disappeared, and which continues to the present day. The Quaternary period began about 2.6 million years ago, and is divided into two major parts: the Pleistocene epoch (Corresponding to The Ice Age), and the post-glacial Holocene epoch, divided at c. 12,000 years ago. A new epoch, the Anthropocene, during which humans have begun to radically influence geological processes, is being considered. Detailed studies have shown that The Ice Age was in fact composed of cold or glacial conditions alternating with interglacial climates as warm, or warmer, than today, each of these alternations lasting tens of thousands of years. In Britain, as elsewhere, this climatic 'restlessness' has had dramatic consequences: as ice sheets have grown and retreated, they have changed sea levels, caused extensive erosion of the earth's crust, movement and deposition of the resulting sediments, caused the crust itself to sink and rise, river systems to drastically change their courses as well as downcutting or infilling their valleys, and forced animal and plant life to migrate, leading in some cases to extinction. </i></span></div><div><span style="color: #0b5394; font-family: verdana;"><i><br /></i></span></div><div><span style="color: #0b5394; font-family: verdana;"><i>Erosion in the British Isles have been very extensive during the Quaternary, so that deposits laid down since the beginning of the period older than about 600,000 years are very fragmentary. In the uplands such as in Scotland and Wales, repeated glacial action has successively modified landforms and removed older Quaternary sediments, resulting in a limited legacy from which to deduce events. In the lower lands of eastern and southern England, where glaciers reached their maximum extents, the landforms and sediments are better-preserved, and the oldest and most diverse record can be found. The Severn Vale and Cotswolds, lying within this tract, has a great variety of Quaternary landforms and deposits, developed over a wide range of time. </i></span></div><div><span style="color: #0b5394; font-family: verdana;"><i><br /></i></span></div><div><span style="color: #0b5394; font-family: verdana;"><i>On this course you will be introduced to these landforms, including anomalous river drainage patterns, dry valleys, river terraces, estuarine platforms and landslides; and deposits laid down by rivers, glaciers, freeze-thaw action, springs, and the Severn Estuary. These deposits are mostly nor normally exposed, but some become temporarily so by human activity e.g for sand and gravel extraction, and ground engineering projects. The tutor has examined a number of these, and their details will be described. Course highlights include the Cotswold scarp being one of the most extensive areas of landsliding in British Isles, and evidence for the Severn Vale not existing prior to the Quaternary. </i></span></div><div><span style="color: #0b5394; font-family: verdana;"><i><br /></i></span></div><div><span style="color: #0b5394;"><span style="font-family: verdana;"><i>A handout outlining the day's programme, and a list of optional suggested reading, would be provided on the course. </i></span></span></div><div><span style="color: #0b5394;"><span style="font-family: verdana;"><i><br /></i></span></span></div><div style="text-align: center;"><span style="color: #0b5394;"><span style="font-family: verdana;"><i><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiaz-NzabJUk8kvXRROAEOi9kaRSk3WEsOuDpDEbOa4ZJchn06fp97adF1V1eHee17GhxiLiGErEcLoaVCM0r_mxpZEASeQYxvG1IXvcV4sWhx3CID7-ALq3EwHcfmaeZhF8fy6oq-F5x8TxeRnkrgozaoq8F6NSBq0kSL0a-wrjFMqmNACqxzuCWi65n4/s1044/distance%20learning%20cold%20gen%20view%20ditchford%20.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="583" data-original-width="1044" height="358" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiaz-NzabJUk8kvXRROAEOi9kaRSk3WEsOuDpDEbOa4ZJchn06fp97adF1V1eHee17GhxiLiGErEcLoaVCM0r_mxpZEASeQYxvG1IXvcV4sWhx3CID7-ALq3EwHcfmaeZhF8fy6oq-F5x8TxeRnkrgozaoq8F6NSBq0kSL0a-wrjFMqmNACqxzuCWi65n4/w640-h358/distance%20learning%20cold%20gen%20view%20ditchford%20.jpg" width="640" /></a></div><br /> </i></span></span><span style="font-family: verdana;"><span style="text-align: left;"><i><span style="color: #0b5394;">Glacial till overlain by outwash gravels. Anglian Glaciation. Gravel pit exposure (now infilled) near Moreton-in-Marsh, Glos. </span></i></span><span style="color: #0b5394;"><i> </i></span><span style="color: #0b5394;"> </span></span></div></div><div style="text-align: center;"><span style="color: #0b5394; font-family: Arial, Helvetica, sans-serif; font-size: x-small;"><br /></span></div><div style="text-align: left;"><span style="color: #0b5394; font-family: Arial, Helvetica, sans-serif; font-size: x-small;">------------------------------------------------------------------</span></div><div style="text-align: left;"><span style="color: #0b5394; font-family: Arial, Helvetica, sans-serif; font-size: x-small;"><br /></span></div><div style="text-align: left;"><div><div><u><span style="color: #0b5394; font-family: verdana;"><i>Sunday 26th November</i></span></u></div><div><span style="color: #0b5394; font-family: verdana;"><i><br /></i></span></div><div><span style="color: #0b5394; font-family: verdana;"><i><b>'Highland Border Geology, Scotland; evidence for a terrane boundary' </b>10.00 am - 5.00 pm </i></span></div></div><div><b><span style="color: #0b5394; font-family: verdana;"><i><br /></i></span></b></div><div><span style="color: #0b5394; font-family: verdana;"><i>Many tectonic plate collision zones around the world contain ‘terranes’: regions of crust with well-defined boundaries, that differ significantly in their geological development from neighbouring regions. Ancient long-since stabilised collision zones globally are often composed of a set of interlocking (often fault-bounded) terranes, each of which originated in different places and had different tectonic histories, but which were progressively amalgamated into the arrangement seen today. The crust of the British Isles is composed of a number of such terranes, brought together by plate collisions that culminated in the ‘Caledonian Orogeny’ (mountain-building episode, Early Silurian – Mid Devonian times). On this course, we trace one of these terrane boundaries along the Highland Border of Scotland between the Isle of Bute (near Glasgow) in the west, to Stonehaven (near Aberdeen) on the east coast. We will look at the character of the two terranes involved, the nature of the boundary between them, evidence for when the terranes were separated, and for when they finally became joined.<br /></i></span></div><div><span style="color: #0b5394; font-family: verdana;"><i><br /></i></span></div><div><span style="color: #0b5394; font-family: verdana;"><i>A handout outlining the day's programme, and a list of optional suggested reading, would be provided on the course. </i></span><span style="font-family: verdana, sans-serif;"><br /></span></div><div><span style="color: #0b5394; font-family: verdana;"><i><br /></i></span></div><div style="text-align: center;"><span style="color: #0b5394; font-family: verdana;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhNhmN9kUzby_R5tn243G1TOd8NKAKpEoRqk-vQRpP1k2LMG10CWX_IwZv9h3DGS3j6W_k_-TS5V31rHmdZI7aoVbDcPp6fO2DF6qd2lCNCeKSUzMP6evejM3gzRnFNUzpE5939TgPqhaEA4cf5iMQ5tPn18a7DtrSlj8IK7lxES5JBDXsiGiQDmdjty7M/s1000/TERRANE%20BOUNDARY%20-%20HIGHLAND%20BORDER,%20SCOTLAND%20.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="398" data-original-width="1000" height="254" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhNhmN9kUzby_R5tn243G1TOd8NKAKpEoRqk-vQRpP1k2LMG10CWX_IwZv9h3DGS3j6W_k_-TS5V31rHmdZI7aoVbDcPp6fO2DF6qd2lCNCeKSUzMP6evejM3gzRnFNUzpE5939TgPqhaEA4cf5iMQ5tPn18a7DtrSlj8IK7lxES5JBDXsiGiQDmdjty7M/w640-h254/TERRANE%20BOUNDARY%20-%20HIGHLAND%20BORDER,%20SCOTLAND%20.jpg" width="640" /></a></div><br /></span><span style="text-align: start;"><span style="color: #0b5394; font-family: verdana; font-size: medium;"><i>Contrasting landscape along the Highland Border, Scotland: low-lying cultivated land of the Midland Valley in the foreground; the rugged Grampian Mountains in the distance. </i></span></span></div><div style="text-align: center;"><span style="text-align: start;"><span style="color: #0b5394; font-family: verdana; font-size: medium;"><i><br /></i></span></span></div><div style="text-align: center;"><span style="text-align: start;"><span style="color: #0b5394; font-family: verdana; font-size: medium;"><i><br /></i></span></span></div><div><span style="color: #0b5394; font-family: verdana;"><i>-----------------------------------------------</i></span></div><div><br style="color: #222222; font-family: Arial, Helvetica, sans-serif; font-size: small;" /></div></div></div><div style="background-color: white;"><span style="color: #0b5394; font-family: verdana;"><br /></span></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-33228797088774190472023-10-05T09:00:00.001+00:002023-10-05T09:00:44.078+00:00What Killed the Dinosaurs?<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> What Killed the Dinosaurs?</span></h1><div><span style="font-family: verdana;">Things are always more complicated than you would like. With the demise of the dinosaurs you chose either the Chicxulub impact or the Deccan traps. If you were being boringly rational you would say both. </span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;"><a href="https://www.science.org/doi/10.1126/science.adh3875#supplementary-materials" target="_blank">THIS PAPER</a> describes a computer exercise to determine whether the Deccan Traps were sufficient to do the job by themselves. And comes to the conclusion that they could. Of course they say that the coincidental timing of the asteroid did not help the dinosaurs, but they would have died out anyway. (To read the full paper you need to be subscribed.)</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">If, like me, you do not have a subscription, read <a href="https://www.wired.com/story/what-killed-the-dinosaurs/?utm_source=Nature+Briefing&utm_campaign=76343d29f1-briefing-dy-20231004&utm_medium=email&utm_term=0_c9dfd39373-76343d29f1-44329857" target="_blank">THIS ARTICLE</a>, which gives details of the work and reactions to it from both pro-volcano and pro-asteroid camps. Well worth reading!</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;"><br /></span></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-71383624203595637732023-09-27T14:55:00.000+00:002023-09-27T14:55:10.109+00:00Mammals Doomed - in 250 Million Years<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> Mammals Doomed - in 250 Million Years</span></h1><div><span style="font-family: verdana;"><a href="https://www.sciencealert.com/the-next-supercontinent-formation-could-wipe-out-most-mammal-life?utm_source=ScienceAlert+-+Daily+Email+Updates&utm_campaign=378de5de44-RSS_EMAIL_CAMPAIGN&utm_medium=email&utm_term=0_fe5632fb09-378de5de44-365599033" target="_blank">THIS ARTICLE</a>, based on <a href="https://www.nature.com/articles/s41561-023-01259-3#Abs1" target="_blank">THIS ACADEMIC PAPER</a>, suggests that in 250 million years a new supercontinent - Pangea Ultima - will form and as a consequence of this CO₂</span></div><div><span style="font-family: verdana;">in the atmosphere will rise. The resulting temperature rise will be sufficient to make mammalian life impossible. There might be hope for burrowing nocturnal rodents living near the poles. (The diagrams indicate that the UK might be a good place if you are a burrowing nocturnal rodent.)</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">The authors (the main one is Bristol based) provide lots of data and discussion, particularly about why </span><span style="font-family: verdana;">CO₂ should rise</span><span style="font-family: verdana;">. Read it for yourself and see if you agree.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">Whether there will be humans around in 250 million years to observe mammalian doom is doubtful. I think we will be long gone by then, seen off by evolution or our stupidity. But, being human, we live to speculate.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;"><br /></span><div class="separator" style="clear: both; font-family: verdana; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi6Bm9uddhTK7KPmsn5E_ty3B6jdfaEwfoR_MeFh4rh0NgGJQGQ0sr5czUtcdzirkMVjuqUYToDYmfH_abNfcJu9ndQUVmcm_KDczIEB8VFDx3G2Zal8DygSNpXh_3B6VuQxJ_aozP7AF-G2sIVJzch5dwswJUbBxFnZtatwgNU9xVNAfVh8rMOCVreBqM/s605/2023-09-27_155136.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="434" data-original-width="605" height="460" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi6Bm9uddhTK7KPmsn5E_ty3B6jdfaEwfoR_MeFh4rh0NgGJQGQ0sr5czUtcdzirkMVjuqUYToDYmfH_abNfcJu9ndQUVmcm_KDczIEB8VFDx3G2Zal8DygSNpXh_3B6VuQxJ_aozP7AF-G2sIVJzch5dwswJUbBxFnZtatwgNU9xVNAfVh8rMOCVreBqM/w640-h460/2023-09-27_155136.jpg" width="640" /></a></div><div style="text-align: center;"><span style="font-family: verdana;"><span style="color: #0b5394;">The habitable Earth in 250 million years - maybe.</span></span></div></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;"><br /></span></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-77562488994499293872023-09-27T14:13:00.002+00:002023-09-27T14:13:17.967+00:00Down to Earth Extra October 2023<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> Down to Earth Extra October 2023</span></h1><div><span style="font-family: verdana;">The October 2023 edition of Down to Earth Extra has been published. You can download it <a href="https://app.box.com/s/xb01ohlbe124pu32ok1kkx0hlfbmvgyv" target="_blank">HERE</a> or you can read it below.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;"><br /></span></div><div style="text-align: center;"><iframe allowfullscreen="" frameborder="0" height="900" msallowfullscreen="" src="https://app.box.com/embed/s/xb01ohlbe124pu32ok1kkx0hlfbmvgyv?sortColumn=date" webkitallowfullscreen="" width="666"></iframe></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-74484762522256825522023-09-23T11:53:00.000+00:002023-09-23T11:53:11.690+00:00It Happened 8 Thousand Years Ago...<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;"> It Happened 8 Thousand Years Ago...</span></h1><div><span style="font-family: verdana;">About 8 thousand years ago things got a lot cooler - 3.3°C cooler. It got cooler because the surface waters of the North Atlantic became fresher - and less heavy.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">Because they are less dense they cannot sink. If they don't sink warmer waters cannot come northwards to replace them. And so northern Europe suffers from a cold Atlantic and temperatures drop. And you get a drought. The technical term for this is "a perturbation of the Atlantic Meridional Overturning Circulation (AMOC)".</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">The cause, 8 thousand years ago, is thought to be the draining of Lake Agassiz in central Canada. Measurements made in the Ythan estuary just north of Aberdeen show sea level rising 2.4 m at 13mm per year around 8.5 thousand years ago.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">Worryingly, the same thing is happening now, but with a different cause. The Greenland is cap is melting. It rained on the top of the ice cap (3.2km in elevation) in 2021 for the first time ever!</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">At first sight the fall in temperature because of global warming might seem to be a good thing. But I doubt it. Adding chaos to chaos is seldom beneficial.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">Read all about this in <a href="https://earthlogs.org/2023/09/22/sudden-climate-change-a-warning-from-8-millennia-ago/" target="_blank">THIS ARTICLE</a>.</span></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0tag:blogger.com,1999:blog-7506056614065490208.post-3261934961012764372023-09-14T18:46:00.001+00:002023-09-14T18:46:40.679+00:00Was the PETM Linked to Hydrothermal Venting?<h1 style="text-align: center;"><span style="color: #990000; font-family: verdana; font-size: x-large;">Was the PETM Linked to Hydrothermal Venting? </span></h1><div><span style="font-family: verdana;">The PETM (Palaeocene-Eocene Thermal Maximum) was a period of rapid global warming. Sea surface temperatures rose 6°C within 10 to 20 thousand years. This rate of temperature rise is not very different to what is happening currently. As <a href="https://earthlogs.org/2023/09/14/direct-signs-of-what-caused-the-palaeocene-eocene-thermal-maximum/" target="_blank">THIS ARTICLE</a> says, the temperature rise led to the release of organic carbon into the atmosphere. Expressed as CO₂, 0.24 gigatons (Gt) per year. Currently we release 0.51Gt per year. The article is based on <a href="https://www.dropbox.com/scl/fi/2dc1xbyhs1zvc4d7mvtzx/s41561-023-01246-8.pdf?rlkey=0sxfi1nqkz8s7f5zygsc5o5h0&dl=0" target="_blank">THIS PDF</a>.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">In the PETM the temperature rise led to the most dramatic biologic changes since the asteroid killed the dinosaurs.</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">What was the cause? At the time there was magmatic activity around the area which was to become the Atlantic. This was the start of continental rifting. Much of the activity was the intrusion of sills. Could the sills have led to the release of methane from organic rich sediments?</span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">The article suggests that is what happened. Using a 3-D seismic survey they found pockmarks beneath the P-E boundary. Detailed study suggests they formed from hydrothermal venting. </span></div><div><span style="font-family: verdana;"><br /></span></div><div><span style="font-family: verdana;">Because they happened in shallow water the CH₄ went straight into the atmosphere. (At depth it would have been mitigated by the methane being oxidised to carbon dioxide.)</span></div><div><span style="font-family: verdana;"><br /></span></div><div style="text-align: center;"><div class="separator" style="clear: both; text-align: center;"><a href="https://earthlog1.files.wordpress.com/2023/09/3d-seismic.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="510" data-original-width="800" height="408" src="https://earthlog1.files.wordpress.com/2023/09/3d-seismic.jpg" width="640" /></a></div><br /><span style="color: #0b5394; font-family: verdana;">Three-dimensional view of seismic reflection data off western Norway. The greytone lower part is a vertical ‘slice’. The coloured part shows the depth variation of sediments that fill hydrothermal vent systems beneath a horizontal unconformity. (Credit: Berndt et al, Fig 1b)</span></div>Graemehttp://www.blogger.com/profile/13725221769790940627noreply@blogger.com0