Antarctica’s ice shelves could be melting up to 40 percent faster than we thought due to ocean currents along its coast, a new study warns.
Scientists in California have created a new climate model that takes into account the impact of a coastal current called Antarctic Coastal Current (ACC).
The researchers say this narrow current causes warm water to melt Antarctica’s ice shelves — floating ice platforms around the Antarctic coast.
Their model suggests that ice shelf melt rates are 20 to 40 percent higher than previous predictions from other climate models.
Ice shelves protect against the uncontrolled release of inland ice into the ocean, so if they melt, it could ultimately contribute to faster sea-level rise.
According to the results of a new climate model, Antarctica’s ice shelves could be melting up to 40 percent faster than we thought, thanks to ocean currents along the coast. Ice shelves are floating pieces of ice attached to land-based ice sheets and help protect against the uncontrolled release of inland ice into the ocean
Antarctica is home to a number of ice shelves marked on this map, including Amery, Shackleton, and Ross. The formations can also be found along the Arctic coasts
WHAT IS AN ICE SHELF?
Ice shelves are permanently floating ice shelves that connect to a landmass.
Most of the world’s ice shelves lie along the coast of Antarctica.
However, ice shelves can also form anywhere where ice flows from land into cold ocean waters, including some glaciers in the Northern Hemisphere.
Source: National Snow and Ice Data Center
The new study, published Friday in the journal scientific progressis led by experts from Caltech and JPL in California.
“If this mechanism we’ve studied is active in the real world, it could mean the ice shelf melt rate is 20 to 40 percent faster than predictions in global climate models, which typically cannot simulate these strong currents near Antarctica.” . coast,” said study author Andy Thompson of Caltech.
Ice shelves are large floating ice platforms connected to a landmass, such as Antarctica, although they can also be found in other polar locations such as Greenland.
The shelves act as a protective buffer for the ice on the mainland, preventing the entire Antarctic ice sheet from flowing into the ocean, which would dramatically raise global sea levels.
However, a warming atmosphere and warming oceans caused by climate change are increasing the rate at which these ice shelves are melting, threatening their ability to hold back the flow of the ice sheet into the ocean.
For their study, the team focused on an area of Antarctica called the West Antarctic Peninsula.
Antarctica is roughly disk-shaped, except where the peninsula juts out from the high polar latitudes and into lower, warmer latitudes.
It is here that Antarctica is seeing the most dramatic changes due to climate change.
The team has previously deployed autonomous vehicles in this region, and scientists have used data from elephant seals with instruments attached to them to measure the temperature and salinity in the water and ice.
Ice shelves are permanently floating ice shelves that connect to a landmass. Pictured is the Ross Ice Shelf, Antarctica’s largest ice shelf
The team created a computer model that takes into account an often overlooked narrow ocean current along the Antarctic coast called the Antarctic Coastal Current.
Known as the southernmost current in the world, the Antarctic Coastal Current runs counterclockwise around the entire Antarctic continent.
But many climate models do not take into account the Antarctic coastal current because it is relatively narrow – about 20 km.
‘Most climate models only capture flows of 100 kilometers’ [62 miles] about or bigger,” said study author Mar Flexas at Caltech.
“So those models may not accurately reflect future melt rates.”
A distant ice shelf as researchers measure temperature and salinity off the coast of Antarctica
WHAT IS FRESH WATER?
Freshwater is water that contains only minimal amounts of dissolved salts, which distinguishes it from seawater or brackish water.
It is found in glaciers, lakes, reservoirs, ponds, rivers, streams, wetlands and even groundwater.
Only 3 percent of all water on Earth is fresh water.
Freshwater is threatened by overdevelopment, polluted runoff and global warming.
Source: Green Facts/WWF
The computer model showed how fast flowing fresh water, melted from the ice shelves, can trap dense warm ocean water at the base of the ice, causing it to warm up and melt even more.
It illustrates how freshwater melting from ice on the West Antarctic Peninsula is carried by the Antarctic Coastal Current and transported around the continent.
The less dense freshwater moves quickly along the ocean’s surface and traps relatively warm ocean saltwater against the underside of the ice shelves, causing the ice shelves to melt from below.
Essentially, increased meltwater in the West Antarctic Peninsula can generate climate warming via the Antarctic Coastal Current, which in turn can also escalate melting, even on ice shelves thousands of miles away from the peninsula.
This distant warming mechanism may be part of the reason that the volume loss of the West Antarctic ice shelves has accelerated in recent decades.
“There are aspects of the climate system that we are still discovering,” Thompson said.
“As we have made progress in our ability to model interactions between the ocean, ice shelves and atmosphere, we are able to make more accurate predictions with better constraints on uncertainty.
Researchers traveling to Antarctica to measure ocean temperature and salinity
“Maybe we need to revise some of the sea-level rise predictions in the coming decades or century — that’s work we’ll be doing in the future.”
The new findings follow another study published Wednesday in Nature that says Antarctica’s ice shelves are “crumbling” and have declined significantly over the past 25 years.
According to the study, about 12 trillion tons of ice have been lost in the past 25 years, which is double the previous estimate.
We know that one cause of the retreat of ice shelves is the thinning of ice shelves, which is largely caused by relatively warm seawater eroding the bottoms of these shelves,” two of the authors wrote. The conversation this week.
SCIENTISTS FIND GROUNDWATER IN SEDIMENTS DEEP UNDER ANTARCTIC ICE
For the first time, scientists have found a vast groundwater system under ice in Antarctica.
The groundwater reservoir lies beneath the Whillans Ice Stream in West Antarctica, US experts say.
Groundwater is fresh water (from rain or melting ice and snow) that soaks into the ground and is stored in the small spaces (pores) between rocks and soil particles.
Such groundwater systems are likely to be common in Antarctica, influencing how the continent responds to climate change — though researchers aren’t quite sure how.
According to the team, under similar conditions, groundwater may exist on other planets or moons that release heat from their interiors.
Read more: Scientists find groundwater in sediments deep beneath Antarctic ice