Geology Today最新文献

{"title":"A beachcomber's bonanza, or just another Micraster?","authors":"Stephen K. Donovan","doi":"10.1111/gto.12402","DOIUrl":"10.1111/gto.12402","url":null,"abstract":"<p>The beach is where the ancient, in the shape of diverse erratics, meets the present in the shape of corrosion, encrusting shells and invertebrate borings. Many of us have favourite beach walks, repeated whenever possible, and educating us in the common and rare clasts that might be encountered in such an ever-changing environment. After over 12 years of patrolling the coast of north Norfolk, in eastern England, I found a common Chalk echinoid—so why am I excited?</p>","PeriodicalId":100581,"journal":{"name":"Geology Today","volume":"38 4","pages":"143-146"},"PeriodicalIF":0.0,"publicationDate":"2022-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91476918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Planetary geology: an historical and philosophical overview","authors":"Hely Cristian Branco,&nbsp;Fernando Mancini","doi":"10.1111/gto.12401","DOIUrl":"10.1111/gto.12401","url":null,"abstract":"<p>The use of geological interpretations to better understand features that are observed outside the Earth defines what is known as planetary geology. It is a highly multi-disciplinary field, using concepts from many areas of human knowledge to better understand the many objects of the Universe. Interpretations tend to be based on analogue models, created from observations made on the Earth and extrapolated to the many geological contexts of other celestial bodies. It is assumed that these models can always be used, as long as corrections considering differences in properties such as temperature, mass, atmospheric, crustal and mantel composition, amongst others, are made. In most cases, such correlations are possible, requiring minor to no significant modifications. However, a reasonable number of extra-terrestrial features cannot be explained using the Earth as the unique comparison ground, requiring the use of other analogues as a basis, or even the creation of models and theories from scratch. Here, we present an overview of planetary geology: what it is, the limits of its application, the current state of the art and the meaning of this line of research in the era in which we live, where the exploration of other objects of the Solar System is a reality.</p>","PeriodicalId":100581,"journal":{"name":"Geology Today","volume":"38 4","pages":"134-142"},"PeriodicalIF":0.0,"publicationDate":"2022-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79340577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geodigest","authors":"","doi":"10.1111/gto.12400","DOIUrl":"10.1111/gto.12400","url":null,"abstract":"The Tonga underwater volcano that erupted in January 2022, covering the island nation in ash, is still surprisingly intact, scientists have said (Holly Bancroft, The Independent, 23 May 2022). The 15 January eruption (Fig. 1) was as powerful as the 1883 Krakatoa eruption in Indonesia and triggered a tsunami, which swept through Tonga and caused widespread damage to buildings. A New Zealand-led team of scientists have been mapping the underwater volcano and discovered that it has not changed much following the eruption, the BBC reported. The expedition leader, marine geologist Kevin Mackay, said he was taken aback by the data that his team had recovered. ‘Given the violence of the eruption on 15 January, I’d expected the edifice to either have collapsed or been blown apart, and this is not the case’, he told the BBC. ‘While the volcano appeared intact, the seafloor showed some dramatic effects of the eruption’. The scientists found that, though the flanks of the volcano were devoid of marine life, fish and mussels were living on other seamounts. Malcolm Clark, a fisheries expert, said that this showed the ‘resilience of animal populations in the region’. The team will be using a robot boat to examine the volcano. They are taking the precaution because it appears to still be active. The eruption of this volcano, named Hunga Tonga-Hunga Ha’apai, has baffled scientists. Researchers are finding it hard to explain why the volcano sent a cloud to such extreme heights, but emitted less ash than would be expected. Volcanologist Nico Fournier, said: ‘It just basically rips the BandAid on our lack of understanding of what’s happening under water’.","PeriodicalId":100581,"journal":{"name":"Geology Today","volume":"38 4","pages":"122-133"},"PeriodicalIF":0.0,"publicationDate":"2022-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78515170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"James Hutton's concept of time: that of Leibniz, not Newton","authors":"Roger D. K. Thomas","doi":"10.1111/gto.12389","DOIUrl":"10.1111/gto.12389","url":null,"abstract":"<p>It is well known that James Hutton's approach to the study of what would later be known as Earth science was significantly influenced by the work of Isaac Newton. But it is hardly appreciated, except perhaps in continental Europe, that Gottfried Leibniz had as much or greater influence on Hutton's ‘natural philosophy’ and even his methods of research and analysis. Nowhere is this more apparent than in the shaping of Hutton's understanding of the nature of time itself.</p>","PeriodicalId":100581,"journal":{"name":"Geology Today","volume":"38 3","pages":"108-111"},"PeriodicalIF":0.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89768712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The lost titan of Cauvery","authors":"Saurabh Pal,&nbsp;Krishnan Ayyasami","doi":"10.1111/gto.12390","DOIUrl":"10.1111/gto.12390","url":null,"abstract":"<p>In 1987, authors P. Yadagiri and K. Ayyasami described a giant dinosaur, <i>Bruhathkayosaurus matleyi</i>, from the Late Cretaceous beds of the Cauvery Basin, India. Unfortunately, the fossil remains of this giant had disintegrated into dust before they reached the repository, making <i>B. matleyi</i> a dubious species. Gigantism is one of the many characteristic features of dinosaurs that grab public attention, and there is much fossil evidence that suggests gigantism was not limited to any specific group of dinosaurs. Nevertheless, this characteristic feature was very advanced and extensive among sauropod dinosaurs, which belonged to a group of long necked herbivorous dinosaurs. Sauropods evolved from basal saurischian dinosaurs about 200 Ma and survived until the K/Pg (Cretaceous–Palaeogene) mass extinction event, about 66 Ma. By the Late Jurassic period, many colossal size sauropods had evolved, such as <i>Supersaurus</i>, <i>Diplodocus</i>, <i>Barosaurus</i>, etc. but together with other Diplodocidae, they went extinct by the end of the Late Jurassic. During the Cretaceous, a new clade of sauropod dinosaurs evolved, the Titanosauria. The Titanosauria diversified into various genera, and in terms of size, they ranged from a 6-m-long <i>Magyarosaurus</i>, to the 35-m-long <i>Argentinosaurus</i>. Most of these giant titanosaurs, including <i>Argentinosaurus</i>, alongside <i>Patagotitan</i>, <i>Dreadnoughtus</i>, <i>Puertasaurus</i>, and <i>Futalognkosaurus</i>, are known from South America, making this continent truly a ‘land of giants’ during the Cretaceous. However, the latest discoveries of this group indicate that supersized titanosaurs were not just restricted to South America, with <i>Paralititan</i> from Africa and <i>Australotitan</i> from Australia. Loss of the fossil remains of <i>B. matleyi</i> has raised not only questions upon the validity of the species, but also questions the notion that any supersized dinosaur lived in India. Here we critically review pieces of evidence in support of supersize dinosaur remains from Southern India.</p>","PeriodicalId":100581,"journal":{"name":"Geology Today","volume":"38 3","pages":"112-116"},"PeriodicalIF":0.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88577417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The 2021 eruption of the Cumbre Vieja volcanic ridge on La Palma, Canary Islands","authors":"Juan C. Carracedo,&nbsp;Valentin R. Troll,&nbsp;James M. D. Day,&nbsp;Harri Geiger,&nbsp;Meritxell Aulinas,&nbsp;Vicente Soler,&nbsp;Frances M. Deegan,&nbsp;Francisco J. Perez-Torrado,&nbsp;Guillem Gisbert,&nbsp;Esteban Gazel,&nbsp;Alejandro Rodriguez-Gonzalez,&nbsp;Helena Albert","doi":"10.1111/gto.12388","DOIUrl":"10.1111/gto.12388","url":null,"abstract":"<p>Almost exactly half a century after the eruption of the Teneguía Volcano on La Palma (26 October to 28 November 1971), a new eruption occurred on the island and lasted for 85 days from 19 September until 13 December 2021. This new eruption opened a volcanic vent complex on the western flank of the Cumbre Vieja rift zone, the N-S elongated polygenetic volcanic ridge that has developed on La Palma over the last <i>c</i>. 125 ka. The Cumbre Vieja ridge is the volcanically active region of the island and the most active one of the Canary Islands, hosting half of all the historically recorded eruptive events in the archipelago. The 2021 La Palma eruption has seen no direct loss of human life, thanks to efficient early detection and sensible management of the volcanic crisis by the authorities, but more than 2800 buildings and almost 1000 hectares of plantations and farmland were affected by lava flows and pyroclastic deposits. Satellite surveillance enabled accurate mapping of the progressive buildup of the extensive and complex basaltic lava field, which together with monitoring of gas emissions informed the timely evacuation of local populations from affected areas. Lava flows that reached the sea constructed an extensive system of lava deltas and platforms, similar to events during earlier historical eruptions such as in 1712, 1949 and 1971. Long-term challenges in the aftermath of the eruption include protection of drainage systems from potential redistribution of tephra during high rainfall events, the use of the large surplus quantities of ash in reconstruction of buildings and in agriculture, and the crucial concerns of where and how rebuilding should and could occur in the aftermath of the eruption. Finally, there remain strong financial concerns over insurance for properties consumed or damaged by the eruption in the light of future volcanic hazards from the Cumbre Vieja volcanic ridge.</p>","PeriodicalId":100581,"journal":{"name":"Geology Today","volume":"38 3","pages":"94-107"},"PeriodicalIF":0.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78578246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geodigest","authors":"","doi":"10.1111/gto.12392","DOIUrl":"10.1111/gto.12392","url":null,"abstract":"","PeriodicalId":100581,"journal":{"name":"Geology Today","volume":"38 3","pages":"82-93"},"PeriodicalIF":0.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90465702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geohazards explained 10","authors":"Ugur Ozturk","doi":"10.1111/gto.12391","DOIUrl":"10.1111/gto.12391","url":null,"abstract":"<p>On the eve of the new year, 2021, a single landslide claimed 70 souls in Ask, a village in Norway. This tragic event highlighted, once again, the need to understand whether research efforts to map landslide susceptible areas could help save lives and if these identified landslide-prone regions change with time. A landslide is a downslope gravitational mass wasting of earth materials. Hence, a classification model could estimate the likelihood of a landslide occurring under certain terrain conditions studying the landslide predisposing factors, such as hillslope inclination and land cover, of old landslides. Projecting these likelihoods in a landscape would be a landslide susceptibility map, which highlights areas that could potentially generate a landslide without any implication of an occurrence time. However, landslide predisposing factors change over time, resetting those susceptibility estimates—they are not static as traditionally assumed by most models. These changes could be evident, such as artificial alterations in land cover, or disguised, such as accumulated damage on hillslopes in the form of subsurface cracks due to a large earthquake. In times referred to as legacy effects, those latter hidden effects could be assessed by studying the spatial distribution of those landslides triggered by the same event. This perspective lists several potential biases of the time-invariant landslide susceptibility approach and offers hints to overcome these challenges using a more dynamic model that evolves.</p>","PeriodicalId":100581,"journal":{"name":"Geology Today","volume":"38 3","pages":"117-120"},"PeriodicalIF":0.0,"publicationDate":"2022-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89213156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Classic localities explained 25","authors":"Michael J. Simms","doi":"10.1111/gto.12385","DOIUrl":"10.1111/gto.12385","url":null,"abstract":"<p>Britain's geology is perhaps more diverse than any equivalent area in the world, spans almost 3 billion years, and has been studied for more than two centuries yet, for too long, it seemed that we could find no evidence here for one of the most spectacular events on the Earth—a giant meteorite impact. Perhaps, the only evidence might be localized and easily overlooked, like the thin layer of millimetre-scale microtektites, once molten beads of rock blasted out by an impact, found near Bristol in 2001. Alas, these proved actually to have originated more than a thousand kilometres from Britain, in the 100 km Manicouagan Crater in eastern Canada. However, just a few years later, a spectacular discovery revealed that a world-class impact deposit, metres thick and extending for tens of kilometres, had been hiding in plain sight at a location visited by countless geology students and their teachers. For decades, the Assynt region in northwest Scotland has been a training ground for geologists, drawn by the immensely old Lewisian Gneiss, the spectacular hills of Torridon sandstone that overlie it, and the structural complexity of the Moine Thrust Zone. How could this remarkable impact deposit have gone unnoticed for so long?</p>","PeriodicalId":100581,"journal":{"name":"Geology Today","volume":"38 2","pages":"75-79"},"PeriodicalIF":0.0,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86248016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geodigest","authors":"","doi":"10.1111/gto.12381","DOIUrl":"10.1111/gto.12381","url":null,"abstract":"The Matterhorn appears to be a massive, immovable mountain towering over the landscape near Zermatt, Switzerland, for millennia (Fig. 1). However, new research led by the WSL Institute for Snow and Avalanche Research SLF in Switzerland shows that this impression is wrong and that the Matterhorn is in fact constantly in motion, swaying gently back and forth approximately every 2 seconds (Andrei Ionescu, Earth.com, 23 December 2021). This subtle vibration with imperceptible amplitudes is caused by seismic energy in the Earth originated from oceans, earthquakes and human activity. Each object, including mountains, high-rise buildings, or bridges, vibrates at certain frequencies when affected by seismic energy. These natural frequencies depend on the geometry and material properties of the object. ‘We wanted to know whether such resonant vibrations can also be detected on a large mountain like the Matterhorn’, said the study lead author Samuel Weber, a researcher at the WSL Institute. Weber and his colleagues installed several seismometers on the Matterhorn, including one just below the summit, at 14 665 feet above sea level, and recorded all movements of the mountain at a high resolution in order to derive the frequency and direction of resonance. They found that the Matterhorn oscillates in a north–south direction at a frequency of 0.42 Hz, and in an east–west direction at a similar frequency. Compared to the reference station at the foot of the mountain, the measured movements on the summit were up to 14 times stronger. This phenomenon is due to the fact that the summit moves freely, while the base of the mountain is fixed, like a tree swaying in the wind. The researchers warn that such movements can intensify during earthquakes and potentially cause damage. ‘Areas of the mountain experiencing amplified ground motion are likely to be more prone to landslides, rockfall and rock damage when shaken by a strong earthquake’, said study co-author Jeffrey Moore, an assistant professor of Geology and Geophysics at the University of Utah. Such vibrations are not a peculiarity of this specific mountain. Other peaks, such as the Grosse Mythen, which is significantly smaller than the Matterhorn, vibrate in a similar manner. In fact, since it is smaller, the Grosse Mythen vibrates at a frequency four times higher than the Matterhorn. The Matterhorn is the largest mountain shown to vibrate. ‘It was exciting to see that our simulation approach also works for a large mountain like the Matterhorn and that the results were confirmed by measurement data’, concluded Moore.","PeriodicalId":100581,"journal":{"name":"Geology Today","volume":"38 2","pages":"42-57"},"PeriodicalIF":0.0,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83906992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}