DIA DE REFLEXÃO NA EUROPA - O APOCALIPSE RUSSO AINDA DEMORA MAIS UNS TEMPOS E O GELO NUNCA MAIS ESTALA NESTA GUERRA FRIA 2014-2018

no news are Bad News 

ONE MILE OF ICE TO MELT on Ice Melt: This Time Greenland

May 19, 2014

Illustration showing newly revealed topography of subsealevel glacial channels in Greenland, from the new Nature Geoscience paper by Morlighem, Rignot et al Note below sea level “bowl” in the interior.

Eric Rignot and his team strike again. This time Greenland.  More vulnerable to melt, more sea level rise likely.  Yadda Yadda.

The bed topography beneath the Greenland ice sheet controls the flow of ice and its discharge into the ocean. Outlet glaciers move through a set of narrow valleys whose detailed geometry is poorly known, especially along the southern coasts. As a result, the contribution of the Greenland ice sheet and its glaciers to sea-level change in the coming century is uncertain. Here, we combine sparse ice-thickness data derived from airborne radar soundings with satellite- derived high-resolution ice motion data through a mass conservation optimization scheme . We infer ice thickness and bed topography along the entire periphery of the Greenland ice sheet at an unprecedented level of spatial detail and precision. We detect widespread ice-covered valleys that extend significantly deeper below sea level and farther inland than previously thought. Our findings imply that the outlet glaciers of Greenland, and the ice sheet as a whole, are probably more vulnerable to ocean thermal forcing and peripheral thinning than inferred previously from existing numerical ice-sheet models. 

Basic issue – Greenland is essentially a ring of mountains surrounding a bowl of ice.
 Where fingers of the sea can reach in beneath the ice and get to the soft underbelly, glacial outflow can proceed really quickly.....NO BECAUSE IS SOME ISOSTATIC COMPENSATION
AND STRESS RELATED FAULTS THAT GOING ON AND OFF

New paper indicates there’s a lot more fingers than we thought, and longer.
This possibility was discussed in my video last year by the ever-prescient Dr.Mike MacCracken.

Greenland’s icy reaches are far more vulnerable to warm ocean waters from climate change than had been thought, according to new research by UC Irvine and NASA glaciologists. The work, published today in Nature Geoscience, shows previously uncharted deep valleys stretching for dozens of miles under the Greenland Ice Sheet.
The bedrock canyons sit well below sea level, meaning that as subtropical Atlantic waters hit the fronts of hundreds of glaciers,THEY GOING TO GO FROM WARM SUBTROPICAL TO 4ºC
AND SINK....AND WATER COLD AND  WITH LOW DENSITY GOING TO APPEAR IN GREAT AMOUNTS AT THE SURFACE... those edges will erode much further than had been assumed and release far greater amounts of water.

Ice melt from the subcontinent has already accelerated as warmer marine currents have migrated north, but older models predicted that once higher ground was reached in a few years, the ocean-induced melting would halt. Greenland’s frozen mass would stop shrinking, and its effect on higher sea waters would be curtailed.

“That turns out to be incorrect. The glaciers of Greenland are likely to retreat faster and farther inland than anticipated – and for much longer – according to this very different topography we’ve discovered beneath the ice,” said lead author Mathieu Morlighem, a UCI associate project scientist. “This has major implications, because the glacier melt will contribute much more to rising seas around the globe.”

To obtain the results, Morlighem developed a breakthrough method that for the first time offers a comprehensive view of Greenland’s entire periphery. It’s nearly impossible to accurately survey at ground level the subcontinent’s rugged, rocky subsurface, which descends as much as 3 miles beneath the thick ice cap.

Since the 1970s, limited ice thickness data has been collected via radar pinging of the boundary between the ice and the bedrock. Along the coastline, though, rough surface ice and pockets of water cluttered the radar sounding, so large swaths of the bed remained invisible.

Measurements of Greenland’s topography have tripled since 2009, thanks to NASA Operation IceBridge flights. But Morlighem quickly realized that while that data provided a fuller picture than had the earlier radar readings, there were still major gaps between the flight lines.

To reveal the full subterranean landscape, he designed a novel “mass conservation algorithm” that combined the previous ice thickness measurements with information on the velocity and direction of its movement and estimates of snowfall and surface melt.

The difference was spectacular. What appeared to be shallow glaciers at the very edges of Greenland are actually long, deep fingers stretching more than 100 kilometers (almost 65 miles) inland.

“We anticipate that these results will have a profound and transforming impact on computer models of ice sheet evolution in Greenland in a warming climate,” the researchers conclude.

“Operation IceBridge vastly improved our knowledge of bed topography beneath the Greenland Ice Sheet,” said co-author Eric Rignot of UC Irvine and NASA’s Jet Propulsion Laboratory. “This new study takes a quantum leap at filling the remaining, critical data gaps on the map.”

The team also reported stark new findings last week on accelerated glacial melt in West Antarctica. Together, the papers “suggest that the globe’s  sheets will contribute far more to sea level rise than current projections show,” Rignot said.

BOMB THE Large-scale fractures related to inception of the

Yellowstone hotspot AND STOP THE MELTING

Jonathan M.G. Glen

U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025, USA, and Berkeley

Geochronology Center, 2455 Ridge Road, Berkeley, California 94709, USA

David A. Ponce

U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025, USA

ABSTRACT

During middle Miocene time, western North America was subject to flood-basalt vol-

canism, dike-swarm injection, and broad-scale fracturing and folding of the crust. We

propose a simple model to account for these events and for a regional pattern of geologic

and geophysical features. Aeromagnetic maps reveal some of the most important elements

of this pattern, which are several narrow, arcuate anomalies, here referred to as the

Northern Nevada rifts. These rifts extend hundreds of kilometers across Nevada and are

likely caused by highly magnetic, middle Miocene mafic dikes. With the aid of filtering

techniques, the anomalies can be traced into Oregon. Together with other geologic fea-

tures, such as fold axes, dike swarms, and faults, they produce a spoke-like pattern fanning

over 220

of arc that converges toward a point near the Oregon-Idaho border

A possible cause for this pattern is a point source of stress at the base of the crust related

to the formation of the Yellowstone hotspot. The spoke-like pattern, however, does not

persist at large distances from the emerging hotspot; several hundred kilometers to the

south, the Northern Nevada rifts deviate significantly (From a radial trend. We show

that a simple model—imposing a point source of stress at the base of the crust and a

regional stress field aligned with the presumed middle Miocene stress direction—fits the

observed fracture pattern. It thus accounts for both the radial pattern present near the

nascent hotspot and the far-field pattern due to regional stresses.

Keywords:

Yellowstone hotspot, Northern Nevada rifts, Snake River Plain, dike swarm, flood

basalts, Columbia River Plateau.

INTRODUCTION

Among the most striking geophysical fea-

tures of western North America (Figs. 1 and

2) are long and narrow positive magnetic

anomalies (collectively referred to here as

the Northern Nevada rifts