Satellite Data Shows Antarctic Ice Shelves Consist of More Meltwater Than Previously Estimated

Antarctic region is our planet’s coldest place, containing the largest ice mass. Antarctic ice shelf is very important for stabilizing the glacier flow from the continent to the ocean. Satellite data helps scientists to track and analyse changes. Recent satellite data reveals more of its actual state, showing that this shelf contains more meltwater than previously estimated.

What is the significance of Antarctic ice shelves?

An ice shelf is an extension of continental ice sheets floating on the ocean. It is like a buttress that holds back glaciers from flowing into the sea. When a shelf collapses, glaciers behind it accelerate and contribute to rising sea levels. A prime example of such collapse is the Larsen B Ice Shelf in 2002. This event led to a rapid discharge of glaciers that the Antarctic shelf previously restrained.

Recent satellite data has been very helpful in monitoring Antarctic shelf levels. Modern satellites are equipped with synthetic aperture radars (SAR) and high-resolution cameras that capture detailed data and images about the shelf surface. Such technologies allow scientists to detect any changes in shelf thickness. At the same time, they provide details on the Antarctic ice shelf’s melting map and meltwater amounts.

How much ice melts in Antarctica each year?

Recently, Antarctic shelf levels have been experiencing unprecedented melting because global temperatures are still rising. According to studies, about 150 billion tons of ice melt in the Antarctic region each year. Antarctic meltwater forms streams and pounds on icy surfaces, leading to hydrofracture – a process in which water-filled cracks propagate through the shelf and potentially cause its disintegration.

Automated mapping techniques have significantly advanced, enabling almost real-time tracking of changes in Antarctic shelf levels. Google Earth Engine (GEE) platform has given us important information on Antarctic ice shelves melting today. It provides a comprehensive view of the latest seasonal developments every year. According to a “Nature Geoscience” study, satellite data reveals that Antarctic shelf levels hold twice as much meltwater as was previously estimated. This meltwater is not only pure liquid but also includes slush and water-soaked snow.

What is the new cause of melting Antarctica ice shelves?

The primary cause of melting that causes Antarctic ice shelf collapse is climate change. According to satellite data, global temperatures are rising, and warming is happening faster at our planet’s poles. For this reason, glaciers and ice sheets don’t only melt but also shrink. While the Antarctic region holds a lot of snow and ice, its levels are dwindling.

This year, Antarctic shelf maps reveal extensive meltwater coverage, especially during summer. According to these maps, the meltwater pond distribution is extending. This information is very important if we want to understand ongoing changes happening in the Antarctic region. Satellite maps highlight areas like the Antarctic Peninsula and the Amery Ice Shelf, where meltwater is more prevalent.

How much has Antarctica melted in the last 10 years

In the last ten years, the overall Antarctic shelf lost over 2,190 gigatons of ice. But there’s still another question we should ask. How many ice shelves does Antarctica have? So far, roughly about 45 major shelves with a few small ones. The major ones are Ross Ice Shelf, Larsen Ice Shelf, and Thwaites Ice Shelf.

Antarctic shelves are formed where ice streams and glaciers flow from land into the sea. Here, they form thick ice-floating platforms. Their role is to slow down the water flow from land into the ocean. Changes like cracking, thinning, or disintegration in shelf levels indicate how climate change impacts global sea level rise.

How much meltwater is in the Antarctic region?

Even with advanced satellite data, it’s currently difficult to quantify the exact amount of meltwater because this continent is vast. Present estimates show about 65 cubic kilometres (km³) of meltwater annually. There’s variability in melting locations and rates, though. However, scientists use ever-improving methods such as field measurements, climate models, and satellite observations to estimate how much water is melting in the Antarctic region.

For example, during summer, melting happens on the surface, especially in coastal areas. Meltwater exists beneath ice sheets, which are formed by geothermal heat. Melt ponds and lakes that form on the Antarctic shelf surface can drain through the ice, contributing to shelf destabilization. Studies use climate models and satellite data to estimate how the Antarctic region produces this amount of meltwater every year, from surface melt alone. According to recent data, there are over 400 subglacial lakes under the Antarctic ice sheet, and these all contain a water volume that’s difficult to determine.

However, our scientific tools keep advancing, which means that, soon enough, we might be able not only to estimate the exact rate of the Antarctic ice shelf melting but also to find a solution to this growing problem.