Diamonds may be ‘forever’ but some may have formed more recently than geologists thought. A study of 26 diamonds, formed under extreme melting conditions in the Earth’s mantle, found two populations, one of which has geologically ‘young’ ages. The results show that certain volcanic events on Earth may still be able to create super-heated conditions previously thought to have only existed early in the planet’s history before it cooled. The findings may have implications for diamond prospecting.
Results indicate climate models where the initiation of glaciation depends strongly on CO2concentrations over astronomical controls significantly overpredict the duration of the present-day warm period compared to past interglacial analogs.
by Arthur Viterio, 2016, in J Earth Science Climate Change
Earth’s climate is a remarkably “noisy” system, driven by scores of oscillators, feedback mechanisms, and radiative forcings. Amidst all this noise, identifying a solitary input to the system (i.e., HGFA MAG4/6 seismic activity as a proxy for geothermal heat flux) that explains 62% of the variation in the earth’s surface temperature is a significant finding.
The discovery of volcanoes under the Antarctic ice sheet may be old news, but now we have evidence that at least some of them have recently (geologically speaking) erupted…
The international team, including palaeontologist from The University of Manchester, found a new set of trace fossils left by some of the first ever organisms capable of active movement. Trace fossils are the tracks and burrows left by living organisms, not physical remains such as bones or body parts.
We describe late Miocene tetrapod footprints (tracks) from the Trachilos locality in western Crete (Greece), which show hominin-like characteristics. They occur in an emergent horizon within an otherwise marginal marine succession of Messinian age (latest Miocene), dated to approximately 5.7 Ma (million years), just prior to the Messinian Salinity Crisis.
Banded iron formations were a prevalent feature of marine sedimentation ~3.8–1.8 billion years ago and they provide key evidence for ferruginous oceans. The disappearance of banded iron formations at ~1.8 billion years ago was traditionally taken as evidence for the demise of ferruginous oceans, but recent geochemical studies show that ferruginous conditions persisted throughout the later Precambrian, and were even a feature of Phanerozoic ocean anoxic events.
A natural global warming event that took place 56 million years ago was triggered almost entirely by volcanic eruptions that occurred as Greenland separated from Europe during the opening of the North Atlantic Ocean,
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The amount of carbon released during this time was vast—more than 30 times larger than all the fossil fuels burned to date and equivalent to all the current conventional and unconventional fossil fuel reserves we could feasibly ever extract.” Ridgwell said.
An unexpected finding was that enhanced organic matter burial was important in ultimately sequestering the released carbon and accelerating the recovery of the Earth’s ecosystem without massive extinctions.
(…) “Nevertheless, we need to be clear that the changes in temperature are gradual, and that recovery can take hundreds of thousands of years. Given the rapid increase in the rate of global warming at present, this kind of wait is not an option for us”.
La comparaison des fluctuations du CO2 atmosphérique retracées à partir de ces estimations avec des courbes des changements de température a révélé de fortes baisses du CO2 atmosphérique (200-300 ppm), couplées à de fortes hausses de la température moyenne à la surface du globe (5-8°C) à l’échelle de quelques millions d’années.
by James E Kamis, August 23, in ClimateChangeDispatch
The now three-year-old Plate Climatology Theory is on the brink of total confirmation. This is the result of two just-released and very telling Antarctic research studies. Combining the results of these two studies with the massive amounts of pre-existing data it is possible to show with very high certainty that melting of West Antarctic glaciers is directly related to bedrock heat flow and chemically charged heated fluid flow from the 5,000-mile-long West Antarctic Rift System (see Figure 1).
Researchers have used computer simulations to analyse how plate tectonics have evolved on Earth over the last three billion years. They show that tectonic processes have changed in the course of the time, and demonstrate how those changes contributed to the formation and destruction of continents. The model reconstructs how present-day continents, oceans and the atmosphere may have evolved.
If “the supervolcano threat is substantially greater than the asteroid or comet threat,” does this mean we can stop fretting about Gorebal Warming and the Sixth Mass Extinction? Is NASA really moving on to actual threats to the planet? Well, not threats to the planet… The planet has handled supervolcanoes, asteroids and comets quite well over its 4.5 billion year lifespan.
The ‘Rise of Algae’ created food webs with more efficient nutrient and energy transfers, driving ecosystems towards larger and increasingly complex organisms. This effect is recorded by the concomitant appearance of biomarkers for sponges and predatory rhizarians, and the subsequent radiation of eumetazoans in the Ediacaran period.
A Triceratops or Tyrannosaurus rex bulling its way through a pine forest likely dislodged flowers that 100 million years later have been identified in their fossilized form as a new species of tree.
While we obsess about climate change and debate if we live in the Anthropocene, we prepare poorly or not at all for natural forces like volcanoes that can level cities. This is folly we can no longer afford. Experts recommend a simple first step to better protect ourselves. Let’s start listening, or nature will teach us an expensive lesson.
The Edinburgh volcano survey, reported in the Geological Society’s special publications series, involved studying the underside of the west Antarctica ice sheet for hidden peaks of basalt rock similar to those produced by the region’s other volcanoes. Their tips actually lie above the ice and have been spotted by polar explorers over the past century.
Since 1600, 278,880 people have been killed by volcanic activity, with many of these deaths attributed to secondary hazards associated with the main eruption. Starvation killed 92,000 following the 1815 Tambora eruption in Indonesia, for example, and a volcanic tsunami killed 36,000 following the 1883 Krakatoa eruption.
Research shows that volcanic activity has shown no let up since the turn of the 21st century – it just hasn’t been around population centres. Indeed, there remain a number of volcanoes poised to blow which pose a major threat to life and livelihood.
An article just published in the Proceedings of the Royal Society B describes two remarkably different hydrothermal vent fields discovered in the southern Gulf of California. Despite being relatively close together, these vents host very different animal communities. This finding contradicts a common scientific assumption that neighboring vents will share similar animal communities. Instead, the new paper suggests that local geology and the chemistry of the vent fluids are important factors affecting vent communities
Detailed pattern correlation of Earth’s temperature changes during the past 450 kyrs reveals observations about several cyclic climate patterns. The past four glacial cycles are increasing in duration from 89 kyrs to 119 kyrs. Within these glacial cycles, two warm periods occur about 200 kyrs apart and have strikingly similar temperature characteristics.
During the last 450 kyrs, the five major warm onsets with rapidly increasing temperatures are triggered by increases in the eccentricity, obliquity, and precession of Earth’s orbit. The nearly concurrent increase in these three astronomical forces appears a necessary component for a major warm onset. Obliquity is the dominate control for ending these major warm periods and entering a cooling phase.
Australia is often thought of as an ancient and quiescent continent — the sleeping giant in a world where landscapes dramatically change in front of our very eyes.
In the Bay of Naples, Europe’s most notorious giant is showing signs of reawakening from its long slumber.
Campi Flegrei, a name that aptly translates as “burning fields”, is a supervolcano. It consists of a vast and complex network of underground chambers that formed hundreds of thousands of years ago, stretching from the outskirts of Naples to underneath the Mediterranean Sea. About half a million people live in Campi Flegrei’s seven-mile-long caldera, which was formed by vast eruptions 200,000, 39,000, 35,000 and 12,000 years ago.
The discovery pushed back the time for the emergence of microbial life on land by 580 million years and also bolstered a paradigm-shifting hypothesis laid out by UC Santa Cruz astrobiologists David Deamer and Bruce Damer: that life began, not in the sea, but on land.
The Permian geologic period that ended the Paleozoic era climaxed around 252 million years ago with a sweeping global mass extinction event in which 90 to 95 percent of marine life became extinct. It would take 30 million years for planetary biodiversity to recover. Understanding the contributing factors of the end-Permian mass extinction is critical to understanding and perhaps mitigating the current anthropogenic climate change.
The discovery by researchers from Imperial could lead to a range of improvements including advances in Carbon Capture and Storage (CCS). This is where industrial emissions will be captured by CCS technology, before reaching the atmosphere, and safely stored in rock deep underground.
