Current:Home > StocksScientists count huge melts in many protective Antarctic ice shelves. Trillions of tons of ice lost.-DB Wealth Institute B2 Expert Reviews
Scientists count huge melts in many protective Antarctic ice shelves. Trillions of tons of ice lost.
View Date:2024-12-23 22:36:47
Four dozen Antarctic ice shelves have shrunk by at least 30% since 1997 and 28 of those have lost more than half of their ice in that time, reports a new study that surveyed these crucial “gatekeepers’’ between the frozen continent’s massive glaciers and open ocean.
Of the continent’s 162 ice shelves, 68 show significant shrinking between 1997 and 2021, while 29 grew, 62 didn’t change and three lost mass but not in a way scientists can say shows a significant trend, according to a study in Thursday’s Science Advances.
That melted ice, which usually pens larger glaciers behind it, then goes into the sea. Scientists worry that climate change -triggered melt from Antarctica and Greenland will cause dangerous and significant sea rise over many decades and centuries.
“Knowing exactly how, and how much, ice is being lost from these protective floating shelves is a key step in understanding how Antarctica is evolving,” said University of Colorado ice scientist Ted Scambos, who wasn’t part of the study.
Scambos said the study gives insight into fresh water that’s melting into the Amundsen Sea — “the key region of Antarctica for sea level rise” — that not only adds height to the ocean, but makes it less dense and salty.
The biggest culprits were giant icebergs breaking off in 1999, 2000 and 2002 that were the size of Delaware, he said. The study also looks at ice melting from warm water below.
Ice shelves are floating extensions of glaciers that act “like the gatekeepers” and keep the larger glacier from flowing more quickly into the water, the study’s lead author said.
All told, Antarctic ice shelves lost about 8.3 trillion tons (7.5 trillion metric tons) of ice in the 25-year period, the study found. That amounts to around 330 billion tons (300 billion metric tons) a year and is similar to previous studies.
But the overall total is not the real story, said study lead author Benjamin Davison, a glaciologist at the University of Leeds in the United Kingdom.
What’s most important, he said, are the patterns of individual shelf loss. The new study shows the deep losses, with four glaciers losing more than a trillion tons on the continent’s peninsula and western side.
“Some of them lost a lot of their mass over time,” Davison said. “Wordie is barely an ice shelf anymore.”
The Wordie ice shelve, which holds back four glaciers near the tip of the Antarctic Peninsula, had a big collapse in 1989, but has lost 87% of its remaining mass since 1997, Davison found. Neighboring Larsen A has lost 73% and Larsen B 57%. The largest of the Larsen ice shelves, Larsen C, has lost 1.8 billion tons (1.7 trillion metric tons) of ice, about one-eighth of its mass.
The biggest loss of all is in the Thwaites ice shelf, holding back the glacier nicknamed Doomsday because it is melting so fast and is so big. The shelf has lost 70% of its mass since 1997 — about 4.1 trillion tons (3.7 trillion metric tons) — into the Amundsen Sea.
The ice shelves that grew were predominantly on the continent’s east side, where there’s a weather pattern isolates the land from warmer waters, Davison said. The ice shelves on the east were growing slower than the shelves losing ice to the west.
It’s difficult to connect an individual ice shelf loss directly to human-caused climate change, but steady attrition is expected as the world warms, he said.
___
Read more of AP’s climate coverage at http://www.apnews.com/Climate
___
Follow Seth Borenstein on Twitter at @borenbears
___
Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.
veryGood! (42627)
Related
- FC Cincinnati player Marco Angulo dies at 22 after injuries from October crash
- The Best Early Memorial Day Sales 2023: Kate Spade, Nordstrom Rack, J.Crew, Coach, BaubleBar, and More
- How the Harvard Covid-19 Study Became the Center of a Partisan Uproar
- Republican Will Hurd announces he's running for president
- Arizona Supreme Court declines emergency request to extend ballot ‘curing’ deadline
- Robert Ballard found the Titanic wreckage in 1985. Here's how he discovered it and what has happened to its artifacts since.
- Wildfires Trap Thousands on Beach in Australia as Death Toll Rises
- Missing sub pilot linked to a famous Titanic couple who died giving lifeboat seats to younger passengers
- Kristin Cavallari's Ex Mark Estes Jokingly Proposed to This Love Island USA Star
- Kim Kardashian Reacts to Kanye West Accusing Her of Cheating With Drake
Ranking
- NFL Week 10 injury report: Live updates on active, inactive players for Sunday's games
- Arctic Report Card 2019: Extreme Ice Loss, Dying Species as Global Warming Worsens
- West Virginia governor defends Do it for Babydog vaccine lottery after federal subpoena
- Creating a sperm or egg from any cell? Reproduction revolution on the horizon
- Jared Goff stats: Lions QB throws career-high 5 INTs in SNF win over Texans
- The Texas Legislature approves a ban on gender-affirming care for minors
- Vanderpump Rules' Tom Sandoval Claims His and Ariana Madix's Relationship Was a Front
- Here's what's on the menu for Biden's state dinner with Modi
Recommendation
-
Brittany Cartwright Defends Hooking Up With Jax Taylor's Friend Amid Their Divorce
-
How Federal Giveaways to Big Coal Leave Ranchers and Taxpayers Out in the Cold
-
How Federal Giveaways to Big Coal Leave Ranchers and Taxpayers Out in the Cold
-
Study Links Short-Term Air Pollution Exposure to Hospitalizations for Growing List of Health Problems
-
Get Your Home Holiday-Ready & Decluttered With These Storage Solutions Starting at $14
-
Barbie's Star-Studded Soundtrack Lineup Has Been Revealed—and Yes, It's Fantastic
-
Khloe Kardashian and Tristan Thompson’s Baby Boy’s Name Finally Revealed 9 Months After Birth
-
Farewell, my kidney: Why the body may reject a lifesaving organ