Some of the earliest complex organisms on Earth — possibly some of the earliest animals to exist — got big not to compete for food, but to spread their offspring as far as possible.
The research, led by the University of Cambridge, found that the most successful organisms living in the oceans more than half a billion years ago were the ones that were able to ‘throw’ their offspring the farthest, thereby colonising their surroundings. The results are reported in the journal Nature Ecology and Evolution.
Prior to the Ediacaran period, between 635 and 541 million years ago, life forms were microscopic in size, but during the Ediacaran, large, complex organisms first appeared, some of which — such as a type of organism known as rangeomorphs — grew as tall as two metres.
Antarctic ice sheet is melting, but rising bedrock below could slow it down
An international team, led by DTU Space at the Technical University of Denmark with Colorado State University, has found that the bedrock below the remote West Antarctic Ice Sheet is rising much more rapidly than previously thought, in response to ongoing ice melt.
The study, “Observed rapid bedrock uplift in the Amundsen Sea Embayment promotes ice-sheet stability,” reveals new insights on the geology of the region and its interaction with the ice sheet and is published in the journal Science. The authors noted that the findings have important implications in understanding and predicting the stability of the ice sheet and Earth’s rising sea levels.
From ARS Technica, one of the most incoherent things I’ve ever read…
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The shocking thing is that Howard Lee has a degree in geology. The fact that he makes his living as an “Earth Science writer” and not as a geologist might just be relevant.
Can the Miocene tell our future? I’ll let Bubba’s mom answer that question:
Water, H2O, determines the ‘General Background Temperature’ for the Earth, resulting in Hothouse and Ice House Climate States. During geological periods the movement of continents changes the position of
continents, oceans and seas. Because of the different configurations, a dominant warm or a dominant cold deep-water production configuration ‘sets’ average temperatures for the deep oceans. Changing vertical oceanic circulation changes surface temperatures, especially in the higher latitudes. During a Hot House State, higher temperatures in the high latitudes result in a high water-vapor concentration that prevents a rapid loss of thermal energy by the Earth.
These three processes, plate tectonics (continental drift), vertical oceanic circulation variability and variations in atmospheric water vapor concentration and distribution, caused previous Hot House and Warm House Climate States. A change in the working of those mechanisms resulted in a transition from the previous Hot House Climate State to the very cold ‘Ice House State’ that we live in now. That change was set in motion by the changing configuration of continents, oceans and seas.
After half a billion million years of climate change, I’m shocked, shocked I tell you, that life on Earth (and specifically corals) have so many ways to cope with the climate changing. After all, it’s natural (if you are trained by Greenpeace) to assume that corals can only survive in a world with one constant stable temperature just like they never had.
One more tool in the coral-reef-workshop
Corals don’t just have a tool-box, they have a Home Depot Warehouse. h/t to GWPF
Global climate change, fueled by skyrocketing levels of atmospheric carbon dioxide, is siphoning oxygen from today’s oceans at an alarming pace — so fast that scientists aren’t entirely sure how the planet will respond.
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Millions of years ago, scientists discovered, powerful volcanoes pumped Earth’s atmosphere full of carbon dioxide, draining the oceans of oxygen and driving a mass extinction of marine organisms.
Le Précambrien représente 88% de l’histoire de la Terre âgée de 4,567 milliards d’années (Ga).
C’est au cours de cette période peu connue, peu enseignée que se sont déroulés ou mis en place des événements physico-chimiques et biologiques déterminants: différenciation des enveloppes terrestres, tectonique des plaques et premières ‘pangées’ ou supercontinents, champ magnétique, chaînes de montagnes, glaciations, anoxies des bassins, remplacement du CO2-CH4par l’oxygène atmosphérique, formation de gisements (uranium, manganèse, nickel …. et même pétrole), émergence dès 3,8 Ga des procaryotes puis des eucaryotes …
Vu l’absence de fossiles stratigraphiques, et donc de biozones, la stratigraphie du Précambrien est encore très difficile, elle est intialement basée sur la lithostratigraphie. De grands progrès ont récemment été réalisés grâce à la chimiostratigraphie istotopique (C, O, Sr….) en plus de la radiométrie absolue.
L’exposé se consacrera aux événements sédimentaires liés au Grand Evénement de l’Oxygène il y a environ 2,5-2,1 Ga (Paléoprotérozoïque) et à ceux liés à la ‘Terre Boule de Neige’ (Snowball Earth) avec la glaciation marinoenne il y a 0,635 Ga (Néoprotérozoïque), à partir des séries de l’Afrique de l’Ouest.
By Field Museum, May 24, 2018 in ScienceDaily (CurrentBiology)
Sixty-six million years ago, the world burned. An asteroid crashed to Earth with a force one million times larger than the largest atomic bomb, causing the extinction of the dinosaurs. But dinosaurs weren’t the only ones that got hit hard — in a new study, scientists learned that the planet’s forests were decimated, leading to the extinction of tree-dwelling birds.
By investigating fossils, Prof. Kießling and Dr. Carl Reddin, who is also at GeoZentrum Nordbayern, have shown that coral, molluscs, and sponges have been following their preferred cold and warm zones for half a billion years. Isotherms (geographic lines denoting the same temperature, for example 20°C) shift towards the poles or the equator as soon as the global temperature rises or decreases. Isotherms have been shifting towards the poles for several years due to global warming.
The tendency towards climate-related migration is most apparent in tropical species. This may be due to the fact that several of these species live near the thermal maximum for complex organisms of 35-45°C . Current global warming trends are driving marine animals towards the poles, provided there is a suitable habitat they can migrate to.
Scientists drilling deep into ancient rocks in the Arizona desert say they have documented a gradual shift in Earth’s orbit that repeats regularly every 405,000 years, playing a role in natural climate swings. Astrophysicists have long hypothesized that the cycle exists based on calculations of celestial mechanics, but the authors of the new research have found the first verifiable physical evidence. They showed that the cycle has been stable for hundreds of millions of years, from before the rise of dinosaurs, and is still active today. The research may have implications not only for climate studies, but our understanding of the evolution of life on Earth, and the evolution of the Solar System. It appears this week in the Proceedings of the National Academy of Sciences.
The research, published in Science Advances, suggests that early animals diversified within a climate similar to that in which the dinosaurs lived.
This interval in time is known for the ‘Cambrian explosion’, the time during which representatives of most of the major animal groups first appear in the fossil record. These include the first animals to produce shells, and it is these shelly fossils that the scientists used.
Data from the tiny fossil shells, and data from new climate model runs, show that high latitude (~65 °S) sea temperatures were in excess of 20 °C. This seems very hot, but it is similar to more recent, better understood, greenhouse climates like that of the Late Cretaceous Period.
by J.E. Kamis, May 7, 2018 in ClimateChangeDispatch
The inclusion of the here-termed West Antarctic Volcano and Fault Belt into the Pacific Ring of Fire will raise scientific awareness concerning the idea, as per the Plate Climatology Theory, that geologically induced heat flow is the root cause of many anomalous changes in Antarctica’s ecosystems, oceans, climate, and ice masses.
When Earth’s tectonic style transitioned from stagnant lid (single plate) to the modern episode of plate tectonics is important but unresolved, and all lines of evidence should be considered, including the climate record. The transition should have disturbed the oceans and atmosphere by redistributing continents, increasing explosive arc volcanism, stimulating mantle plumes and disrupting climate equilibrium established by the previous balance of silicate‐weathering greenhouse gas feedbacks. Formation of subduction zones would redistribute mass sufficiently to cause true polar wander if the subducted slabs were added in the upper mantle at intermediate to high latitudes. The Neoproterozoic Snowball Earth climate crisis may reflect this transition. The transition to plate tectonics is compatible with nearly all proposed geodynamic and oceanographic triggers for Neoproterozoic Snowball Earth events, and could also have contributed to biological triggers. Only extraterrestrial triggers cannot be reconciled with the hypothesis that the Neoproterozoic climate crisis was caused by a prolonged (200–250 m.y.) transition to plate tectonics.
IBRA, Oman — In the arid vastness of this corner of the Arabian Peninsula, out where goats and the occasional camel roam, rocks form the backdrop practically every way you look.
But the stark outcrops and craggy ridges are more than just scenery. Some of these rocks are hard at work, naturally reacting with carbon dioxide from the atmosphere and turning it into stone.
Veins of white carbonate minerals run through slabs of dark rock like fat marbling a steak. Carbonate surrounds pebbles and cobbles, turning ordinary gravel into natural mosaics.
Even pooled spring water that has bubbled up through the rocks reacts with CO2 to produce an ice-like crust of carbonate that, if broken, re-forms within days.
Scientists say that if this natural process, called carbon mineralization, could be harnessed, accelerated and applied inexpensively on a huge scale — admittedly some very big “ifs” — it could help fight climate change. Rocks could remove some of the billions of tons of heat-trapping carbon dioxide that humans have pumped into the air since the beginning of the Industrial Age.
In early 2017 scientists announced the discovery of possible desiccation cracks in Gale Crater, which was filled by lakes 3.5 billion years ago. Now, a new study has confirmed that these features are indeed desiccation cracks, and reveals fresh details about Mars’ ancient climate.
“We are now confident that these are mudcracks,” explains lead author Nathaniel Stein, a geologist at the California Institute of Technology in Pasadena. Since desiccation mudcracks form only where wet sediment is exposed to air, their position closer to the center of the ancient lake bed rather than the edge also suggests that lake levels rose and fell dramatically over time.
Yes, islands are disappearing — most recently the five Solomon Islands lost to rising sea levels. But don’t despair just yet. For every island that goes the way of the dodo bird, the Earth is busy creating new islands.
Some erupt into being through volcanic activity. Others grow from ocean sandbars. Still others reveal themselves after glaciers retreat. A few are only temporary, while some materialize and erode on a regular basis. However they’re birthed and however long they last, island-building is part of the amazing mystery of our living, breathing planet.
Here are 10 of Mother Nature’s newest islands formed in the past two decades (and one still in the embryonic stage).
Scientists have long known that steep mountain ranges can draw carbon dioxide (CO2) out of the atmosphere — as erosion exposes new rock, it also starts a chemical reaction between minerals on hill slopes and CO2 in the air, ‘weathering’ the rock and using CO2 to produce carbonate minerals like calcite.
Scientists now have a clearer picture of the Earth’s mantle, thanks to Michigan State University research published in the current issue of Nature Communications (…)
• We quantitatively analyse pre-eruptive intrusion-induced surface deformation from 33 scaled laboratory experiments resulting in eruptions.
• A robust proxy extracted from surface deformation geometry enables systematic predictions of the locations of a subsurface intrusion and imminent eruption.
• Forecasting an eruption location is possible without geodetic modeling but requires volcano monitoring at high spatiotemporal resolution.
A UNLV scientist has discovered the first direct evidence that fluid water pockets may exist as far as 500 miles deep into the Earth’s mantle.
Groundbreaking research by UNLV geoscientist Oliver Tschauner and colleagues found diamonds pushed up from the Earth’s interior had traces of unique crystallized water called Ice-VII.
Researchers have provided new insights into how molten rock (magma) moves through the Earth’s crust to feed volcanic eruptions. Using laboratory experiments involving water, jelly and laser imaging, researchers were able to demonstrate how magma magma flows through the Earth’s crust to the surface through magma-filled cracks called dykes.
A new study on the timescale of plant evolution has concluded that the first plants to colonize the Earth originated around 500 million years ago — 100 million years earlier than previously thought.
For the first four billion years of Earth’s history, our planet’s continents would have been devoid of all life except microbes.
In popular culture, asteroids play the role of apocalyptic threat, get blamed for wiping out the dinosaurs — and offer an extraterrestrial source for mineral mining. But for one researcher, asteroids play an entirely different role: that of time capsules showing what molecules originally existed in our solar system. Having that information gives scientists the starting point they need to reconstruct the complex pathway that got life started on Earth.
Recently a new model-based paper on climate sensitivity was published by Kate Marvel, Gavin Schmidt (the head of NASA GISS) and others, titled ‘Internal variability and disequilibrium confound estimates of climate sensitivity from observations’. It appears to me that the novel part of its analysis is faulty, and that the part which isn’t faulty isn’t novel.
by U. of Kansas, February 2, 2018 in WUWT, A. Watts
On a ho-hum day some 12,800 years ago, the Earth had emerged from another ice age. Things were warming up, and the glaciers had retreated.
Out of nowhere, the sky was lit with fireballs. This was followed by shock waves.
Fires rushed across the landscape, and dust clogged the sky, cutting off the sunlight. As the climate rapidly cooled, plants died, food sources were snuffed out, and the glaciers advanced again. Ocean currents shifted, setting the climate into a colder, almost “ice age” state that lasted an additional thousand years.
Finally, the climate began to warm again, and people again emerged into a world with fewer large animals and a human culture in North America that left behind completely different kinds of spear points.
La géologie, une science plus que passionnante … et diverse
