Archives de catégorie : climate and geology

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: (…)

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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.

Do 40,000 volcanoes matter?

by JoNova, December 5, 2017


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.

Are underwater volcanoes causing global warming? Oceanic eruptions may have a greater effect on climate than first thought

by Richard Gray, February 6, 2015 in MailOnline


 

  • Geophysicists at Columbia University have found underwater volcanoes erupt in regular cycles that range from a fortnight to 100,000 years
  • They claim that volcanoes on the sea floor are currently experiencing a lull
  • They warn an increase in eruptions will contribute more to climate change 
  • Some climate models have assumed they erupt at a steady rate over time
  • The new research shows they change with the seasons and Earth’s orbit 

 

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Minimal geological methane emissions during the Younger Dryas–Preboreal abrupt warming event

by Vasilii V. Petrenko et al., August 23, 2017 in Nature


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.

New Antarctic heat map reveals sub-ice hotspots

by  A. Dinar, November 13, 2017 in GeoSpace-AGU


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

Potential links between continental rifting, CO2 degassing and climate change through time

by Sascha Brune et al., March 13, 2017 in NatureGeoscience


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.

New map of Antarctic geothermal heat suggests Steig & Mann 2009 weren’t measuring ‘global warming’

by Anthony Watts, November 15, 2017 in WUWT


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.

NASA – Supervolcano may be melting Antarctic ice sheet from below

by Robert, November 10, 2017 in NASA


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

Site of asteroid impact changed the history of life

by Tohoku University, November 10, 2017 in ScienceDaily


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

Hot News from the Antarctic Underground

by Alan Buis, November, 7, 2017, in JPL, NASA


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.

Oxygen-18 Stability in Foraminifera fossils, implications in paleoclimatology

by Andy May, November 4, 2017


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

Retrograde Accretion of a Caribbean Fringing Reef Controlled by Hurricanes and Sea-level Rise

by P. Blanchon et al., October 12, 2017 in Front.Earth.Sci


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

Tropical explosive volcanic eruptions can trigger El Niño by cooling tropical Africa

by M. Khodri et al., October 3,  2017 in Nature


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

The Correlation of Seismic Activity and Recent Global Warming

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.

See also here

Now available on Amazon: ‘Climate Change: The Facts 2017’

by John Abbot et al., September 2017, in A. Watts, WUWT


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.

Volcanic eruptions drove ancient global warming event

by Marcus Gutjah et al., August 30,  2017 in PhysOrg


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,

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.

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