Antarctica’s ice shelves might be melting as much as 40 per cent faster than we thought resulting from coastal ocean currents, a recent study warns.
Scientists in California have created a recent climate model that accounts for 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 platforms of ice across the Antarctic coastline.
Their model suggests ice shelf melt rates are 20 to 40 per cent higher than previous predictions from other climate models.
Ice shelves help guard against the uncontrolled release of inland ice into the ocean, so in the event that they’re melting, this might eventually contribute to more rapid sea level rise.
Antarctica’s ice shelves might be melting as much as 40 per cent faster than we thought because of coastal ocean currents, in response to results of a recent climate model. Ice shelves are floating sections of ice attached to land-based ice sheets and so they help guard against the uncontrolled release of inland ice into the ocean
Antarctica is home to quite a few ice shelves marked out on this map, including Amery, Shackleton and Ross. The formations are also found along Arctic coastlines
WHAT IS AN ICE SHELF?
Ice shelves are everlasting floating sheets of ice that hook up with a landmass.
Many of the world’s ice shelves hug the coast of Antarctica.
Nonetheless, ice shelves may form wherever ice flows from land into cold ocean waters, including some glaciers within the Northern Hemisphere.
Source: National Snow and Ice Data Center
The brand new study, published on Friday within the journal Science Advances, has been led by experts at Caltech and JPL in California.
‘If this mechanism that we have been studying is lively in the true world, it could mean that ice shelf melt rates are 20 to 40 per cent higher than the predictions in global climate models, which generally cannot simulate these strong currents near the Antarctic coast,’ said study creator Andy Thompson at Caltech.
Ice shelves are large floating platforms of ice that hook up with a landmass, reminiscent of Antarctica, although they’re also present in other polar locations reminiscent of Greenland.
The shelves act as a protective buffer for the mainland ice, keeping the entire Antarctic Ice Sheet from flowing into the ocean, which might dramatically raise global sea levels.
Nonetheless, a warming atmosphere and warming oceans attributable to climate change are increasing the speed at which these ice shelves are melting, threatening their ability to carry back the flow of the ice sheet into the ocean.
For his or her study, the team focused on one area of Antarctica, called the West Antarctic Peninsula.
Antarctica is roughly shaped like a disk, except where the peninsula protrudes out of the high polar latitudes and into lower, warmer latitudes.
It’s here that Antarctica sees essentially the most dramatic changes resulting from climate change.
The team has previously deployed autonomous vehicles on this region, and scientists have used data from elephant seals with instruments attached to them to measure temperature and salinity within the water and ice.
Ice shelves are everlasting floating sheets of ice that hook up with a landmass. Pictured is the Ross Ice Shelf, the biggest ice shelf of Antarctica
The team created a pc model that accounts for an often-overlooked narrow ocean current along the Antarctic coast, the Antarctic Coastal Current.
Known for being the southernmost current on the earth, the Antarctic Coastal Current runs anticlockwise around your complete Antarctic continent.
But many climate models don’t include the Antarctic Coastal Current since it is so narrow, relatively speaking – around 12.5 miles (20 km).
‘Most climate models only capture currents which might be 100 kilometers [62 miles] across or larger,’ said study creator Mar Flexas at Caltech.
‘So, there may be a possible for those models to not represent future melt rates very accurately.’
An ice shelf in the space as researchers take measurements of temperature and salinity off the coast of Antarctica
WHAT IS FRESHWATER?
Freshwater is water that incorporates only minimal quantities of dissolved salts, thus distinguishing it from sea water or brackish water.
It’s present in glaciers, lakes, reservoirs, ponds, rivers, streams, wetlands and even groundwater.
Of all of the water on Earth, just 3 per cent is fresh water.
Freshwater is threatened by over-development, polluted runoff and global warming.
Source: Green Facts/WWF
The pc model showed how rapidly flowing freshwater, melted from the ice shelves, can trap dense warm ocean water at the bottom of the ice, causing it to warm and melt much more.
It illustrates how freshwater that melts from ice on the West Antarctic Peninsula is carried by the Antarctic Coastal Current and transported across the continent.
The less-dense freshwater moves along quickly near the surface of the ocean and traps relatively warm ocean saltwater against the underside of the ice shelves, which in turn causes the ice shelves to melt from below.
Essentially, increased meltwater on the West Antarctic Peninsula can generate climate warming via the Antarctic Coastal Current, which in turn may escalate melting even at ice shelves 1000’s of kilometers away from the peninsula.
This distant warming mechanism could also be a part of the explanation that the lack of volume from West Antarctic ice shelves has accelerated in recent a long time.
‘There are features of the climate system that we’re still discovering,’ Thompson said.
‘As we have made progress in our ability to model interactions between the ocean, ice shelves, and atmosphere, we’re in a position to make more accurate predictions with higher constraints on uncertainty.
Researchers traveling to Antarctica to take measurements of ocean temperature and salinity
‘We may have to revisit a number of the predictions of sea level rise in the subsequent a long time or century – that is work that we’ll do going forward.’
The brand new findings follow one other study published in Nature on Wednesday that said Antarctica’s ice shelves are ‘crumbling’ and have significantly reduced in area during the last 25 years.
Around 12 trillion tonnes of ice being lost over the past 25 years, the study found, which is double the previous estimate.
We all know one explanation for ice shelf retreat is the thinning of ice shelves, which is basically attributable to relatively warm seawater eroding the bottom of those shelves,’ two of the authors wrote for The Conversation this week.
SCIENTISTS FIND GROUNDWATER IN SEDIMENTS DEEP UNDER ANTARCTIC ICE
For the primary time, scientists have found an enormous groundwater system below ice in Antarctica.
The reservoir of groundwater lies beneath the Whillans Ice Stream in West Antarctica, say experts within the US.
Groundwater is fresh water (from rain or melting ice and snow) that soaks into the soil and is stored within the tiny spaces (pores) between rocks and particles of soil.
Such groundwater systems are likely common in Antarctica and affect how the continent reacts to climate change – although researchers do not know exactly how.
Groundwater may exist under similar conditions on other planets or moons which might be releasing heat from their interiors, in response to the team.
Read more: Scientists find groundwater in sediments deep under Antarctic ice