Greenland's southern glaciers have accelerated their march to the Atlantic Ocean over the past decade and now contribute more to the global rise in sea levels than previously estimated, researchers say.
Those faster-moving glaciers, along with increased melting, could account for nearly 17 percent of the estimated 2.5mm annual rise in global sea levels, or twice what was previously believed, said Eric Rignot, of NASA's Jet Propulsion Laboratory in Pasadena, California.
An increase in surface air temperatures appears to be causing the glaciers to flow faster, albeit at the still-glacial pace of 13km to 15km a year at their fastest clip, and dump increased volumes of ice into the Atlantic.
PHOTO: AP
That stepped-up flow accounted for about two-thirds of the net 225km3 of ice Greenland lost last year. That compares with 120km3 in 1996, Rignot said.
Rignot and his study co-author, Pannir Kanagaratnam of the University of Kansas, said their report is the first to include measurements of recent changes in glacier velocity in the estimates of how much ice nearly all of Greenland is losing.
"The behavior of the glaciers that dump ice into the sea is the most important aspect of understanding how an ice sheet will evolve in a changing climate," Rignot said. "It takes a long time to build and melt an ice sheet, but glaciers can react quickly to temperature changes."
Details of the study were being presented yesterday at the annual meeting of the American Association for the Advancement of Science. The study appears today in the journal Science.
The researchers said warmer temperatures boost the amount of melt water that reaches where the glaciers flow over rock.
That extra water lubricates the rivers of ice and eases their downhill movement toward the Atlantic.
They tracked the speeds of the glaciers from space, using satellite data collected between 1996 and last year.
If the warmer temperatures spread to northern Greenland, the glaciers there too should pick up their pace, Rignot and Kanagaratnam wrote.
The only way to stem the loss of ice would be for Greenland to receive increased amounts of snowfall, according to Julian Dowdeswell of the University of Cambridge, who wrote an accompanying article.
Former Nicaraguan president Violeta Chamorro, who brought peace to Nicaragua after years of war and was the first woman elected president in the Americas, died on Saturday at the age of 95, her family said. Chamorro, who ruled the poor Central American country from 1990 to 1997, “died in peace, surrounded by the affection and love of her children,” said a statement issued by her four children. As president, Chamorro ended a civil war that had raged for much of the 1980s as US-backed rebels known as the “Contras” fought the leftist Sandinista government. That conflict made Nicaragua one of
COMPETITION: The US and Russia make up about 90 percent of the world stockpile and are adding new versions, while China’s nuclear force is steadily rising, SIPRI said Most of the world’s nuclear-armed states continued to modernize their arsenals last year, setting the stage for a new nuclear arms race, the Stockholm International Peace Research Institute (SIPRI) said yesterday. Nuclear powers including the US and Russia — which account for about 90 percent of the world’s stockpile — had spent time last year “upgrading existing weapons and adding newer versions,” researchers said. Since the end of the Cold War, old warheads have generally been dismantled quicker than new ones have been deployed, resulting in a decrease in the overall number of warheads. However, SIPRI said that the trend was likely
BOMBARDMENT: Moscow sent more than 440 drones and 32 missiles, Volodymyr Zelenskiy said, in ‘one of the most terrifying strikes’ on the capital in recent months A nighttime Russian missile and drone bombardment of Ukraine killed at least 15 people and injured 116 while they slept in their homes, local officials said yesterday, with the main barrage centering on the capital, Kyiv. Kyiv City Military Administration head Tymur Tkachenko said 14 people were killed and 99 were injured as explosions echoed across the city for hours during the night. The bombardment demolished a nine-story residential building, destroying dozens of apartments. Emergency workers were at the scene to rescue people from under the rubble. Russia flung more than 440 drones and 32 missiles at Ukraine, Ukrainian President Volodymyr Zelenskiy
Indonesia’s Mount Lewotobi Laki-Laki yesterday erupted again with giant ash and smoke plumes after forcing evacuations of villages and flight cancelations, including to and from the resort island of Bali. Several eruptions sent ash up to 5km into the sky on Tuesday evening to yesterday afternoon. An eruption on Tuesday afternoon sent thick, gray clouds 10km into the sky that expanded into a mushroom-shaped ash cloud visible as much as 150km kilometers away. The eruption alert was raised on Tuesday to the highest level and the danger zone where people are recommended to leave was expanded to 8km from the crater. Officers also
RSS