Sentences with phrase «ice retreat starting»

There are the famous data sets: the Vostok ice core drilled in the 1970s that looks back about 400,000 years, the Keeling curve started in 1958, data from satellites that watch sea ice retreat starting around 1979.

Not exact matches

«As the ice sheet rapidly retreated, the hydrates concentrated in mounds, and eventually started to melt, expand and cause over-pressure.

Melting would make the grounding line retreat — this is where the ice on the continent meets the sea and starts to float.

They found that, as seas warmed at the end of the last ice age, Pine Island Glacier retreated to a point where its grounding line — the point where it enters the ocean and starts to float — was perched precariously at the end of a slope.

Why the ice periodically advances — and why it retreats again — is a mystery that glaciologists have only just started to unravel.

When the glacier starts to retreat, the frontal moraines are no longer protected by the ice, and a sort of «geological chronometer» is triggered, as the rocks begin to accumulate beryllium - 10 and helium - 3 produced by particles resulting from cosmic rays.

The unstoppable retreat is the likely start of a long - feared domino effect that could cause the entire ice sheet to melt, whether or not greenhouse gas emissions decline.

The scientific community is now debating whether irreversible retreat has already started at some glaciers draining the West Antarctic ice sheet.

There is evidence that greenhouse gas levels fell at the start of ice ages and rose during the retreat of the ice sheets, but it is difficult to establish cause and effect (see the notes above on the role of weathering).

But as a starting point, I'll propose now — and I'll change this if they disagree — the names of some leading scientists in this field who would NOT say there is sufficient evidence to conclude that human - caused global warming IS the main cause of increasing summer retreats of sea ice (although they would say there is strong likelihood that it will eventually dominate):

Updated, 8:17 p.m. The Arctic seems hot these days, and not just because of rising temperatures and retreating ice, or because President Obama plans to speak at an Arctic policy meeting and visit an Arctic community on an Alaska tour starting Monday.

This season's Arctic ice retreat ranks well behind the extraordinary ice retreat of 2007 and also last year's but remains below the average ice extent for the stretch since 1979, when satellites started monitoring Arctic conditions with some precision.

As IPCC AR4 reports «Most mountain glaciers and ice caps have been shrinking, with the retreat probably having started about 1850 [NB: the end of the «little ice age»].

This investigation uncovered that periods of past methane release likely started occurring as the massive ice sheet over Svalbard - Barents Ice Sheet began retreating some 24 000 years aice sheet over Svalbard - Barents Ice Sheet began retreating some 24 000 years aIce Sheet began retreating some 24 000 years ago.

With respect to retreat of Arctic sea ice, observed retreat is occurring a bit faster than the IPCC set of models is projecting — and some finer - scale models are starting to explain why.

As that ice sheet retreated, some 20,000 years ago, the sea floor started bouncing back.

And remember, the satellite data are one small part of a vast amount of data that overwhelmingly show our planet is warming up: retreating glaciers, huge amounts of ice melting at both poles, the «death spiral» of arctic ice every year at the summer minimum over time, earlier annual starts of warm weather and later starts of cold weather, warming oceans, rising sea levels, ocean acidification, more extreme weather, changing weather patterns overall, earlier snow melts, and lower snow cover in the spring...

What is known is that during the period called Little Ice Age, global glacial were advancing, and starting around 1850, instead advancing global glacier became retreating, this trend of glacial retreat continues to the present time, but not all glaciers adding during the Little Ice Age have not yet melted.

At the same time, as the melt season advances, the importance of solar heating, one of the main drivers of seasonal ice retreat, starts to wane due to increasing cloudiness and lower solar elevations.

After a period with maximum extension of the ESCIS covering the southern Lomonosov Ridge (including the area of cores PS2757 - 8 and PS87 / 086 -3) and causing ice - shelf grounding (ice rise) with no ice algae production underneath (Fig. 6, Scenario 1), the ice shelf started to retreat.

For almost the entire winter, sea ice has been reluctant to form there, and now that the Sun has returned, the ice edge has started to retreat to record high latitudes, past the Bering Strait all the way up into the Chukchi Sea.

The retreat of glaciers in the tropical Andes mountains, with some fluctuations, started after the Little Ice Age (16th to 19th centuries), but the rate of retreat (area reduction between 20 - 50 %) has accelerated since the late 1970s.

But when the Little Ice Age came to an end, it started retreating.

This means that even though little of the ice melts in the summer, still less ice will form in the increasingly snowless winters — and the glaciers start to retreat.

Melting would cause the retreat of the grounding line, where the ice on the solid continental landmass meets the sea and starts to float.

The shape of this slope means that when grounding lines start to retreat, ocean water can infiltrate between the ice and the bed and cause the ice sheet to float off its grounding line.

The ice front gets high enough that gravity starts helping; the entire structure fails and retreats.

Then it will still not be snowing and the ice will start to retreat.

The unintended human consequences, starting with that agriculturally - triggered warming, extending to acquired vulnerability to extreme weather and solar storms, the current global warming, Arctic sea - ice retreat (moment # 97), and coral reef die - offs (moment # 99).

Why did the Antarctic sea ice suddenly retreat at the start of September last year?

When I started looking at this topic the first thing that struck me was just how much time is spent in the blogosphere debating the effects (real or imagined) of global temperature rise and how little time seemed to be spent on the key evidential science; as though retreating glaciers, arctic sea - ice or coral bleaching said anything about causality.