Archives de catégorie : climate and geology

Why did gas hydrates melt at the end of the last ice age?

by GEOMAR Inst., February 12, 2018 in WUWT

GEOMAR researchers find links between sedimentation and methane seeps on the seafloor off the coast of Norway

Large amounts of the greenhouse gas methane are locked up as solid gas hydrates in the continental slopes of ocean margins. Their stability depends on low temperatures and high pressure. However, other factors that influence gas hydrate stability are not as well understood. A German-Norwegian research team has found evidence off the coast of Norway that the amount of sediment deposited on the seafloor can play a crucial role. The study has been published today in the international journal Nature Communications.

Study: Early humans witnessed global cooling, warming, and massive fires from comet debris impacts

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.

Groundbreaking AGW-Undermining Study: Greenland’s Warming, Ice Loss Due To Geothermal Heat

by K. Richard, January 24, 2018 in NoTricksZone

A few years ago, 10 glaciologists publishing in the journal Nature Geoscience asserted that “large parts of the north-central Greenland ice sheet are melting from below” due to high geothermal heat flux forcing (Rogozhina et al., 2016).

In a new paper published in Scientific Reports, 4 more glaciologists (Rysgaardet al., 2018) report that “hot vents” (or hot springs) of geothermally-heated water underneath the Greenland ice sheet can explain localized rising temperatures and glacial melting.

Worse than we thought’ – climate models underestimate future polar warming

by  FLORIDA MUSEUM OF NATURAL HISTORY,  January 23, 2018, in WUWT, A. Watts

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.

Earth’s Rotation Is Mysteriously Slowing Down: Experts Predict Uptick In 2018 Earthquakes

by Tevor Nace, November 20, 2017 in WhoaScience

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.

Seafloor Volcano Pulses May Alter Climate

by Columbia University, February 5, 2015

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

Further proof El Ninos are fueled by deep-sea geological heat flow

by Janes E Kamis, January, 27 in CliateChangeDispatch

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: (…)

See also here

Extinction and global warming 250 million years ago

by U. of Bristol, January 10, 2018 in A Watts, WUWT

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.

Impact of Volcanic Eruptions on Decadal to Centennial Fluctuations of Arctic Sea Ice Extent during the Last Millennium and on Initiation of the Little Ice Age

by J Slawinska and A Robock, November 29, 2017 in AmerMeteorSoc

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.

“Pseudoscience is embraced, it might be argued, in exact proportion as real science is misunderstood”… Except in the case of climate change.

by David Middleton, December 5, 2017

(…) 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.