Sentences with phrase «more glacial ice»

«The meltwater feedback cycle under the ice shelf will only slow down once the shelf has collapsed, or no more glacial ice flows in from inland to take its place.

Not exact matches

Evidence of past glacial advance and retreat is also more easily observed in the Dry Valleys, providing a window into the past behavior of the vast Antarctic ice sheets and their influence on global sea levels.

As a result of such breakups, more than 150 cubic kilometers of glacial ice has slid off land into the ocean.

When floating ice shelves disintegrate, they reduce the resistance to glacial flow and thus allow the grounded glaciers they were buttressing to significantly dump more ice into the ocean, raising sea levels.

The more intensive variations during glacial periods are due to the greater difference in temperature between the ice - covered polar regions and the Tropics, which produced a more dynamic exchange of warm and cold air masses.

The researchers found that during glacial periods when the atmosphere was colder and sea ice was far more extensive, deep ocean waters came to the surface much further north of the Antarctic continent than they do today.

The sediment cores used in this study cover a period when the planet went through many climate cycles driven by variations in Earth's orbit, from extreme glacial periods such as the Last Glacial Maximum about 20,000 years ago, when massive ice sheets covered the northern parts of Europe and North America, to relatively warm interglacial periods with climates more like tglacial periods such as the Last Glacial Maximum about 20,000 years ago, when massive ice sheets covered the northern parts of Europe and North America, to relatively warm interglacial periods with climates more like tGlacial Maximum about 20,000 years ago, when massive ice sheets covered the northern parts of Europe and North America, to relatively warm interglacial periods with climates more like today's.

By 1900, increased emissions of soot could have triggered the loss of more than 15 m of ice from a glacier's surface; by 1930, the loss could have totaled 30 m or more — magnitudes and timing that can easily account for the Alpine glacial retreat, the scientists contend.

Since so much of the ice sheet is grounded underwater, rising sea levels may have the effect of lifting the sheets, allowing more - and increasingly warmer - water underneath it, leading to further bottom melting, more ice shelf disintegration, accelerated glacial flow, and further sea level rise, and so on and on, another vicious cycle.

Leaving aside the collapse of the Larsen - B ice shelf and other ice shelves in Antarctica, is it too simplistic to expect that dramatic changes should be anticipated first in the Arctic because it is sea covered by a few meters of sea ice and therefore more susceptible to change, in comparison to Antarctica (which is obviously land covered by glacial ice up to several kilometers thick in places)?

Methane changes much more quickly than CO2 in the ice core records, through the Younger Dryas for example, which lasted 1000 years, methane goes back to glacial values while CO2 sort of hovers in place.

The abstract doesn't have the room to provide more information on how the melting of glacial ice has weakened part of the volcano, leading to an increased potential for a landslide.

«Conversely, there is more and better evidence across Iceland that when the ice sheet underwent major reduction at the end of the last glacial period, there was a large increase in both the frequency and volume of basalt erupted — with some estimates being 30 times higher than the present day.

Recent research shows that there is high microbial activity on glacial surfaces (Anesio et al., 2009), some associated with pigmented algae, which absorb significantly more light than local inorganic dust particles on the Greenland Ice Sheet (GrIS)(Lutz et al., 2014).

During the Middle Pleistocene, ice sheets were reaching the continental shelf for longer, with more distinct glacial - interglacial cyclicity [28].

However, as a glacial period lengthens, ice sheets become larger, but also more unstable.

With higher precipitation, portions of this snow may not melt during the summer and so glacial ice can form at lower altitudes and more southerly latitudes, reducing the temperatures over land by increased albedo as noted above.

This all - wheel drive, tri-axle ice vehicle transports you safely up to Athabasca Glacier where you'll step out onto glacial ice that could be as old as 200,000 years or more.

In contrast, the much more expansive ice volume maxima (equivalently, sea level minima) during a glacial maximum is more defined.

Methane changes much more quickly than CO2 in the ice core records, through the Younger Dryas for example, which lasted 1000 years, methane goes back to glacial values while CO2 sort of hovers in place.

The bottom line is that climatic change effects are being experienced RIGHT NOW; some are subtle while others are more overt, like glacial retreat, an increase in the severity and unpredictability of weather phenomena, or the North Polar ice cap shrinking to its lowest surface area in history.

Samples of gas trapped in ice cores taken from the Greenland and Antarctic ice sheets have enabled scientists to determine that the level of CO2 in the atmosphere has fluctuated between approximately 180 ppm (glacial advance and colder climate in the higher latitudes) and 280 ppm (glacial retreat and warmer climate in the higher latitudes), over the past 400,000 or more years.

Leaving aside the collapse of the Larsen - B ice shelf and other ice shelves in Antarctica, is it too simplistic to expect that dramatic changes should be anticipated first in the Arctic because it is sea covered by a few meters of sea ice and therefore more susceptible to change, in comparison to Antarctica (which is obviously land covered by glacial ice up to several kilometers thick in places)?

He makes the following statement, which is misleading if not outright wrong: Paleo records shows that both temperature and sea level have been mostly rising since last glacial maximum and more recently, since the so called little ice age.

If I may add one more speculative question: are the portions of glacial sheets formed during periods of high ice flux less stable, and more prone to calving, than those formed during slow flux?

It is also possible for cold climates to increase chemical weathering in some ways, by lowering sea level to expose more land to erosion (though I'd guess this can also increase oxydation of C in sediments) and by supplying more sediments via glacial erosion for chemical weathering (of course, those sediments must make it to warmer conditions to make the process effective — downhill and downstream, or perhaps via pulsed ice ages -LRB-?)-RRB-.

It is true that during ice ages the oceans took up more CO2 and that is why there was less in the atmosphere, and during the warming at the end of glacial cycles that CO2 came back out of the ocean, and this was an important amplifying feedback.

Alarmed at the pace of change to our Earth caused by human - induced climate change, including accelerating melting and loss of ice from Greenland, the Himalayas and Antarctica, acidification of the world's oceans due to rising CO2 concentrations, increasingly intense tropical cyclones, more damaging and intense drought and floods, including glacial lakes outburst loods, in many regions and higher levels of sea - level rise than estimated just a few years ago, risks changing the face of the planet and threatening coastal cities, low lying areas, mountainous regions and vulnerable countries the world over,

From what I've heard has been happening in the Arctic, that sounds more like acceleration too, in the loss of glacial ice, permafrost and sea ice.

Should it be attained, this state would be more «symmetric» than the present climate, with comparable areas of ice / sea - ice cover in each hemisphere, and would represent the culmination of 50 million years of evolution from bipolar nonglacial climates to bipolar glacial climates.

Global average temperature is lower during glacial periods for two primary reasons: 1) there was only about 190 ppm CO2 in the atmosphere, and other major greenhouse gases (CH4 and N2O) were also lower 2) the earth surface was more reflective, due to the presence of lots of ice and snow on land, and lots more sea ice than today (that is, the albedo was higher).

I believe the average life span of a glacial period is 90,000 years and often features NYC under more than a kilometer thick of ice.

* It would take only a small further reduction in climate forcing (less long - lived GHGs or whatever) to yield more ice during the glacial phase of glacial - interglacial oscillations.

The thing is, Antarctic land ice loss will continue and accelerate as glacial terminators erode more and more quickly.

DSL: «The thing is, Antarctic land ice loss will continue and accelerate as glacial terminators erode more and more quickly.

(William: Come on man, the sun is causing what is observed) Phenomena such as the Younger Dryas and Heinrich events might only occur in a «glacial» world with much larger ice sheets and more extensive sea ice cover.

Glacial periods during the 100,000 - year cycles have been characterised by a very slow build - up of ice which took thousands of years, the result of ice volume responding to orbital change far more slowly than the ocean temperatures reacted.

Warm ocean water plays a significant role in melting glacial ice from below, and a better mapping of Antarctica's and Greenland's landforms beneath the ice suggests that ocean melting of the glacier fronts may play a more significant role than previously thought as the ice sheets retreat (under a global warming scenario).

An ice sheet is a mass of glacial land ice extending more than 50,000 square kilometers (20,000 square miles).

This glacial melt heat conveyor is the kind of process we are seeing more and more frequently near the great ice sheets as fossil fuel industry has continued its harmful emissions.

The vertical movements that occurred during retreat of the ice sheets in late glacial time are very much more complex than during postglacial time.

Abrupt and severe temperature shifts have occurred on occasion in the past, typically separated by hundreds of years or more, but shifts of this magnitude that are global in extent have almost always occurred during glacial eras, when the extent of snow and ice allowed for great changes in feedback in response to only modest signals.

The vulnerable nations declared that they are, «Alarmed at the pace of change to our Earth caused by human - induced climate change, including accelerating melting and loss of ice from Greenland, the Himalayas and Antarctica, acidification of the world's oceans due to rising CO2 concentrations, increasingly intense tropical cyclones, more damaging and intense drought and floods, including Glacial Lakes Outburst Floods, in many regions and higher levels of sea - level rise than estimated just a few years ago, risks changing the face of the planet and threatening coastal cities, low lying areas, mountainous regions and vulnerable countries the world over...»

Let's put more distance between ourselves and the last glacial maximum, when great ice sheets stretched over the USA and Europe.

Also, current understanding of glacial ice melting due to global warming indicates that the Western Antarctic...... Read more»

Since glacial ice deforms like very slow putty, the steepening of the glacier would have caused the more mobile, middle section to flow pick up speed.

Clouds modulate Earth's energy budget over millennia and more — second only to runaway ice sheet feedbacks leading to glacials every 100,000 odd years.

A challenge for climate sleuths has been to find a place holding a series of corals dating back into and beyond the last ice age, when sea levels were more than 300 feet lower than they are now because so much water was locked up in glacial ice.

We could, of course, hit some bifurcation in the system where we lose all the summer Arctic sea ice or the Amazon forest, which is bad enough, and could possibly transition the climate to a different «solution» on a hysteresis diagram... this to me would represent more of a step-wise jump (akin to a larger bifurcation that you get in a snowball Earth as you gradually reduce CO2 or the solar constant); but ultimately these represent different behavior than «the interannual variability of the large scale dynamics will increase» or that for some reason the climate should be susceptible to more «flip flops» (as in the glacial Heinrich / D - O events), of which I am aware of no observational or theoretical support.

Overall, when taking a look at these newly realized ice - sheet weaknesses, it's worth noting that the total heat forcing impacting the world's ocean, air, and glacial systems is now rising into a range that is much more in line with Middle Miocene values.