Sentences with phrase «volcanism over»

There are of course other causes for other changes that have occurred, including suspected asteroid impacts, changes in volcanism over the eons which can lead to the buildup or reduction of greenhouse gases over long time scales, etc..

Not exact matches

Scientists had ignored that possibility because until now they assumed seafloor volcanism is constant over time, Lund says.

«When we look at the present day, we have a very high fidelity timeline over the last about 500 million years of what's happened on Earth, and we have a pretty good understanding that plate tectonics and volcanism and all these kinds of processes have happened more or less the same way over the last couple of billion years,» says Lindy Elkins - Tanton, director of the School of Earth and Space Exploration at Arizona State University.

Using Australia's National Computational Infrastructure's supercomputer Raijin, the team created high - resolution three - dimensional simulations of mantle evolution over the past 200 million years to understand the coupling between convection in the deep Earth and volcanism.

«I think the idea of a short catastrophe is incorrect,» agrees Herrick, adding that he leans towards the picture of Venus as a more «normal» planet, with episodes of volcanism wiping out craters over a long time period.

Over the next few billion years, Taylor says, Venus's volcanism will subside, and the planet will begin to lose much of its heavy atmosphere, leading to a lower surface temperature more like that of Earth.

Titanium is especially useful in mapping and understanding volcanism on the Moon because it varies so much in concentration, from less than 1 weight percent TiO2 to over 15 percent.

«And correlating chemistry with age, we can see how the Moon's volcanism changed over time.»

volcanism The processes by which volcanoes form and change over time.

The most commonly accepted current theory about the genesis of the PETM involves a sudden increase in volcanism spewing out tons of carbon over thousands of years.

The Global Volcanism Program have a list of all volcanoes with a Volcanic Explosivity Index (VEI) greater than 4 over the past 10,000 years.

The uncertainty in the overall amplitude of the reconstruction of volcanic forcing is also important for quantifying the influence of volcanism on temperature reconstructions over longer periods, but is difficult to quantify and may be a substantial fraction of the best estimate (e.g., Hegerl et al., 2006a).

An independent, annually dated ice core record of explosive volcanism from WAIS Divide synchronized to EPICA Dome C over the last 27,000 years.

What we will all now over time, or those who come after will know, is that warming and cooling of the climate is almost entirely dependent upon the sun, its activity, our orbit of it, etc... Of course other things such as volcanism matter, and clouds, and water vapor, and so many other things which are all natural and have happened over and over through the ages.

As LST closely tracks air temperatures over the instrumental period, we can also infer that air temperatures in this region of East Africa varied in concert with the global average and thus were controlled primarily by the major forcings influencing temperatures over this timescale, both natural (solar radiation, volcanism) and anthropogenic (greenhouse - gas emissions; refs 19, 20).

The Global Volcanism Program have a list of all volcanoes with a Volcanic Explosivity Index (VEI) greater than 4 over the past 10,000 years.

The long - term eruption data, spread over more than 700,000 years, showed that during the coldest times, when sea levels are low, undersea volcanism surges, producing visible bands of hills.

The West Antarctic Ice Sheet rests over a geologically complex region characterized by thin crust, high heat flows, active volcanism and sedimentary basins (9 - 16).

Some examples from energy balance model calculations indicate that: (1) solar variability has a near - global response, with the amplitude of response slightly larger over land; (2) volcanism has a proportionately larger amplitude of response over land than over ocean; and (3) the most oft - cited mode of internal variability, changes in the North Atlantic thermohaline circulation, has a hemispheric asymmetry in response.

«There are lake records all over the planet, but it's very hard to find that kind of consistent record in the Andes with all the active volcanism and tectonics that happen there.

The natural causes of climate variations that have time scales (century, decadal; e.g. Schwabe sunspot cycles, average solar output during the satellite measuring era,, ENSO / PDO / AMO and the rest of the alphabet soup of «oscillations», volcanism) either don't capture energy over multiple cycles — if I push a child on a swing, his average position doesn't move away from me — or are going in the wrong direction.

There is also a spurious drift over the whole period — possibly caused by anthropogenic water vapour and / or aerosols — and this period had frequent episodes of active volcanism.

Tabulate the CO2 exhalation rates over the last 15,000 years from (i) terrestrial and submarine volcanism (including maars, gas vents, geysers and springs) and calc - silicate mineral formation, and (ii) CH4 oxidation to CO2 derived from CH4 exhalation by terrestrial and submarine volcanism, natural hydrocarbon leakage from sediments and sedimentary rocks, methane hydrates, soils, microbiological decay of plant material, arthropods, ruminants and terrestrial methanogenic bacteria to a depth of 4 km.