The researchers published their findings this week in the Proceedings of the National Academy of Sciences.
Scientists frequently look to the Eocene to understand how the Earth responds to higher levels of carbon dioxide. During the Eocene, the concentration of carbon dioxide in the atmosphere was more than 560 parts per million, at least twice preindustrial levels, and the epoch kicked off with a global average temperature more than 8 degrees Celsius – about 14 degrees Fahrenheit – warmer than today, gradually cooling over the next 22 million years. These characteristics make the Eocene a good period on which to test our understanding of the climate system, said Laura Cotton, study co-author and curator of micropaleontology at the Florida Museum of Natural History.
Scientists have found strong evidence that 2018 will see a big uptick in the number of large earthquakes globally. Earth’s rotation, as with many things, is cyclical, slowing down by a few milliseconds per day then speeding up again.
You and I will never notice this very slight variation in the rotational speed of Earth. However, we will certainly notice the result, an increase in the number of severe earthquakes.
Geophysicists are able to measure the rotational speed of Earth extremely precisely, calculating slight variations on the order of milliseconds. Now, scientists believe a slowdown of the Earth’s rotation is the link to an observed cyclical increase in earthquakes.
Vast ranges of volcanoes hidden under the oceans are presumed by scientists to be the gentle giants of the planet, oozing lava at slow, steady rates along mid-ocean ridges. But a new study shows that they flare up on strikingly regular cycles, ranging from two weeks to 100,000 years—and, that they erupt almost exclusively during the first six months of each year. The pulses—apparently tied to short- and long-term changes in earth’s orbit, and to sea levels–may help trigger natural climate swings. Scientists have already speculated that volcanic cycles on land emitting large amounts of carbon dioxide might influence climate; but up to now there was no evidence from submarine volcanoes. The findings suggest that models of earth’s natural climate dynamics, and by extension human-influenced climate change, may have to be adjusted
The 2014-2017 El Nino “warm blob” was likely created, maintained, and partially recharged on two separate occasions by massive pulses of super-heated and chemically charged seawater from deep-sea geological features in the western North Pacific Ocean. This strongly supports the theory all El Ninos are naturally occurring and geological in origin. Climate change / global warming had nothing to do with generating, rewarming, intensifying, or increasing the frequency of the 2014-2017 El Nino or any previous El Nino.
If proven correct, this would revolutionize climatology and key aspects of many interrelated sciences such as oceanography, marine biology, glaciology, biogeochemistry, and most importantly meteorology. Information supporting a geological origin of El Ninos is diverse, reliable, and can be placed into five general categories as follows: (…)
One of the key effects of the end-Permian mass extinction, 252 million years ago, was rapid heating of tropical waters and atmospheres.
How this affected life on land has been uncertain until now.
In a new study published today, Dr Massimo Bernardi and Professor Mike Benton from the School of Earth Sciences at the University of Bristol show how early reptiles were expelled from the tropics.
We evaluate different hypotheses of the origin of the Little Ice Age, focusing on the long-term response of Arctic sea ice and oceanic circulation to solar and volcanic perturbations. We analyze the Last Millennium Ensemble of climate model simulations carried out with the Community Earth System Model at the National Center for Atmospheric Research. We examine the duration and strength of volcanic perturbations, as well as initial and boundary conditions such as the phase of the Atlantic Multidecadal Oscillation, and their impact on decadal to multi-centennial perturbations of the cryospheric, oceanic, and atmospheric components of the climate system.
(…) Petroleum geologists tend to be sedimentary geologists and sedimentary geology is essentially a combination of paleogeography and paleoclimatology. Depositional environments are defined by physical geography and climate. We literally do practice in a different world, the past. Geologists intuitively see Earth processes as cyclical and also tend to look at things from the perspective of “deep time.” For those of us working the Gulf of Mexico, we “go to work” in a world defined by glacioeustatic and halokinetic processes and, quite frankly, most of us don’t see anything anomalous in recent climate changes.
The scope of our ignorance on the sea floor is really something. There are 1,500 active volcanoes on land, but on the sea floor we are still discovering them all the time. at least 39,000 of them rise one kilometer off the sea floor, but there are suspicions there might be up to 3 million, holey moley. The Hilliers paper estimates that 24,000 submarine volcanoes were not yet discovered in 2007. Wikimedia is trying to list them. Good luck.
Preboreal event was driven by contemporaneous methane from sources such as wetlands; our findings constrain the contribution from old carbon reservoirs (marine methane hydrates8, permafrost9 and methane trapped under ice10) to 19 per cent or less (95 per cent confidence). To the extent that the characteristics of the most recent deglaciation and the Younger Dryas–Preboreal warming are comparable to those of the current anthropogenic warming, our measurements suggest that large future atmospheric releases of methane from old carbon sources are unlikely to occur.
An international team of scientists, led by British Antarctic Survey (BAS), has produced a new map showing how much heat from the Earth’s interior is reaching the base of the Antarctic Ice Sheet. The map is part of a new paper accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.
The team has produced the most up to date, accurate and high-resolution map of the so called ‘geothermal heat flux’ at the base of the Antarctic Ice Sheet. Of the basic information that shapes and controls ice flow, the most poorly known about is this heat
Using a numerical carbon cycle model, we find that two prominent periods of enhanced rifting 160 to 100 million years ago and after 55 million years ago coincided with greenhouse climate episodes, during which atmospheric CO2 concentrations were more than three times higher than today. We therefore propose that continental fragmentation and long-term climate change could plausibly be linked via massive CO2 degassing in rift systems.
This is quite interesting. Remember the claim in on the front cover of Nature in 2009 by Steig and Mann that Antarctica was warming, thanks to that “special Mannian PCA math sauce” that was applied to air temperature data to smear surface temperature trends over the entire continent? It was dashed by climate skeptics who wrote a paper. It was accepted for publication and disproved (in my opinion) by a team of credible skeptics that wrote a counter-paper. But, there’s an interesting twist thanks to new and surprising data; Steig and Mann may have captured surface air temperature trends in the exact same areas that have been identified as geothermal hot spots.
Confirms what I’ve been saying all along!
NASA scientists admit that a massive heat source almost as hot as the Yellowstone supervolcano may be melting the Antarctic ice sheet from below.
It seems like a no-brainer to me. I mean, how can lakes and rivers be flowing beneath the ice unless there’s a heat source down there? And if sub-glacial volcanoes can be melting the ice, why couldn’t underwater volcanoes be heating the sea
An asteroid, also known as the Chicxulub Impactor, hit Earth some 66 million years ago, causing a crater 180 km wide. The impact of the asteroid heated organic matter in rocks and ejected it into the atmosphere, forming soot in the stratosphere.
According to the study, soot from hydrocarbon-rich areas caused global cooling of 8-11°C and cooling on land of 13-17°C. It also caused a decrease in precipitation by approximately 70-85 percent on land and a decrease of approximately 5-7°C in seawater temperature at a 50-m water depth, leading to mass extinction of life forms including dinosaurs and ammonites
Study Bolsters Theory of Heat Source Under West Antarctica
A new NASA study adds evidence that a geothermal heat source called a mantle plume lies deep below Antarctica’s Marie Byrd Land, explaining some of the melting that creates lakes and rivers under the ice sheet. Although the heat source isn’t a new or increasing threat to the West Antarctic ice sheet, it may help explain why the ice sheet collapsed rapidly in an earlier era of rapid climate change, and why it is so unstable today.
18O is a rare isotope of oxygen. The ratio of 18O to the normal 16O in foraminifera fossils (“forams”) can be used to estimate paleo-ocean temperatures. Higher values mean lower temperatures. A recent article on geologypage.com (here) led me to Bernard, et al., 2017, which has experimental data that suggest 18O concentrations can be altered in fossils by solid-state diffusion after fossilization. This can corrupt the measurement and the resulting calculated temperature
Predicting the impact of sea-level (SL) rise on coral reefs requires reliable models of reef accretion. Most assume that accretion results from vertical growth of coralgal framework, but recent studies show that reefs exposed to hurricanes consist of layers of coral gravel rather than in-place corals. New models are therefore needed to account for hurricane impact on reef accretion over geological timescales
Washington State University researchers have determined that the Pacific Northwest was home to one of the Earth’s largest known volcanic eruptions, a millennia-long spewing of sulfuric gas that blocked out the sun and cooled the planet.
Stratospheric aerosols from large tropical explosive volcanic eruptions backscatter shortwave radiation and reduce the global mean surface temperature. Observations suggest that they also favour an El Niño within 2 years following the eruption. Modelling studies have, however, so far reached no consensus on either the sign or physical mechanism of El Niño response to volcanism
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.
Considering the likelihood of future presentations and discussions, an update of paleoclimatological information was overdue. I was amazed to bump into a full overview of the atmospheric CO2 content of the last 420 million years published much earlier this year. An important milestone in the history of climate on Earth
Climate Change: The Facts 2017 contains 22 essays by internationally-renowned experts and commentators, including Dr Bjorn Lomborg, Dr Matt Ridley, Professor Peter Ridd, Dr Willie Soon, Dr Ian Plimer, Dr Roy Spencer, and literary giant Clive James. Anthony Watts also has a chapter.
The volume is edited by Dr Jennifer Marohasy, Senior Fellow at the Institute of Public Affairs. Fourteen of the contributors currently hold or have held positions at a university or a scientific research organisation.
La géologie, une science plus que passionnante … et diverse
