Tag: Petermann Glacier

Greenland seeing unprecedented melting

By Phil Plait | July 24, 2012 11:30 am

Last week, a huge chunk of ice broke off of Greenland’s Petermann glacier, an event called a "calving". The iceberg is now moving down the glacier’s fjord, as seen by NASA’s Terra Earth-observing satellite on July 21, 2012:

Note the scale. The iceberg is well over 100 square kilometers in size – about 50 square miles, or 30,000 acres. That’s larger than the island of Manhattan in New York City. An even larger iceberg broke off in 2010.

This image comes on the heels of an announcement that Greenland is seeing "unprecedented" melting. By July 12, 2012, as much as 97% of Greenland’s ice sheet had experienced some degree of melting. On July 8, just four days earlier, only 40% of the ice had experienced some melting:

[The map shows ice that has had some melting in red, and areas showing no melting in white. The left map is from July 8, the right from July 12.]

This does not mean that 97% of the Greenland ice sheet has melted away! The map shows all the places where at least some melting has occurred. Some of this melting is simply due to it being summer, and in some places there is evidence of a historic cycle of melting. But this widespread a melting has not happened in the 30 years satellites have been used to map the region. Normally, about half the ice on Greenland experiences some melting.

The culprit appears to be several waves of warm high-pressure ridges that have swept over Greenland, each stronger than the last, with the most recent one squatting over the island for about a week.

As always, it’s difficult to pin any specific weather event on global warming. But every day, the list of suspicious events grows longer. The Petermann calving happened much farther up the glacier than has occurred before. Waves of warm air over Greenland are unusual. And the weird weather we’ve been getting is consistent with what’s been predicted for a planet that’s warming up.

And while climate change deniers put up insulting billboards and compare climate scientists to child molesters, the Earth is getting warmer. While antiscience Congressmen write fallacy-laden op-eds and elected officials run witch hunts against scientists, the Earth is getting warmer.

We need serious people in charge, because it’s way, way past time to take this seriously.


Image credits: Terra picture: Jesse Allen and Robert Simmon, using data from NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team; Melting map: Jesse Allen, NASA Earth Observatory and Nicolo E. DiGirolamo, SSAI and Cryospheric Sciences Laboratory


Related Posts:

- Huge glacier calves off Greenland
- Enormous glacier calves in largest Arctic event seen in 48 years (with followups here and here)
- EXCLUSIVE: Michael Mann responds to Rep. Barton
- Five shots against global warming denialism

Huge glacier calves off Greenland

By Phil Plait | July 19, 2012 6:53 am

The Petermann Glacier is a vast tongue of flowing ice in Greenland. In 2010 it calved – broke off a chunk – releasing an iceberg far larger than Manhattan Island in New York City. That huge chunk of ice moved into the ocean and eventually melted in the Atlantic (see Related Posts below for more on that event).

And now Petermann has done it again. A crack appeared several years ago, and on July 16th conditions were right to allow a new chunk to break free:

Note the scale: the width of that glacier at that point is 20 kilometers, or 12 miles.

This iceberg was imaged by NASA’s Aqua satellite, designed to monitor Earth’s oceans. The berg itself is about half the size of the last one, but don’t kid yourself: that’s still huge.

As before, we can speculate whether this is due to global warming or not. Icebergs calf all the time. However, note that the last time, the berg calved later in the summer (August), and this crack is much farther up the glacier than usually seen.

As climate scientist Michael Mann says, global warming is like loaded dice. You don’t know if any particular throw of snake eyes is due to them being fixed, but you’ll see a lot more rolls turn up snake eyes than you would otherwise. Global warming is predicted to give us longer, hotter summers, drier conditions across the US, more record temperatures, thinner arctic ice, and having it cover less surface area of the Earth. And, yes, more frequent glacier calving.

By the way, the 2010 calving event was the largest seen in nearly 50 years. And also by the way, June 2012 was one of the hottest since records have been kept. And also also by the way June 2012 had the highest land and ocean average surface temperatures in the northern hemisphere in recorded history. And oh, one more thing: it also was the 328th consecutive month with a global temperature higher than the 20th century average. You can read all about this in the NOAA report "State of the Climate Global Analysis" for June 2012.

But you global warming deniers, you just go ahead and keep on denying. Keep cherry picking, keep changing the subject, keep misinterpreting graphs, and keep slinging ad hominems (note: that last one is skeevy and foul and disgusting almost beyond belief).

In the meantime those of us who understand the actual situation will take it seriously, and continue to speak out. Because this we know:

The Earth is warming up. The rate of warming has increased in the past century or so. This corresponds to the time of the Industrial Revolution, when we started dumping greenhouse gases into the atmosphere. Greenhouse gases warm the planet (hence the name) — if they didn’t we’d have an average temperature below the freezing point of water. Carbon dioxide is a greenhouse gas which is dumped into the atmosphere by humans to the tune of 30 billion tons per year, 100 times the amount from volcanoes. And finally, approximately 97% of climatologists who actually study climate agree that global warming is real, and caused by humans.


NASA Earth Observatory image by Jesse Allen, using data from the Land Atmosphere Near real-time Capability for EOS (LANCE).


Related Posts:

- Enormous glacier calves in largest Arctic event seen in 48 years
- Ice island heading south off Labrador
- Titanic’s revenge
- New study clinches it: the Earth is warming up

Titanic's revenge

By Phil Plait | September 9, 2011 7:00 am

About a year ago, an enormous iceberg split off the Petermann glacier in Greenland. Taken by the current, it headed south, and just last month was off the coast of Labrador. The iceberg was over 20 km (12 miles) long.

On August 22, NASA’s Terra satellite took a look at it and saw this:

I have nothing much to add here, except to make sure you understand that a chunk of ice significantly bigger than Manhattan Island broke in half.

Ships aren’t alive, and even if they were the existence of their souls would be in doubt. But still, the idea appeals to me that somewhere, somehow, the Titanic is laughing.

Image credit: Jeff Schmaltz, MODIS Rapid Response, NASA Goddard Space Flight Center.


Related posts:

- Enormous glacier calves in largest arctic event seen in 48 years
- Ice island heading south off Labrador
- Titanic iceberg headed for Australia
- Dramatic glacial retreat caught by NASA satellite

CATEGORIZED UNDER: Cool stuff, Pretty pictures

Ice island heading south off Labrador

By Phil Plait | July 5, 2011 7:00 am

This is truly amazing: you may remember that last August, a vast iceberg 25 km long calved off the Petermann glacier. This chunk of ice broke free and has made its way off Labrador and is headed to the north Atlantic.

NASA’s Aqua satellite caught it in the open water:

It looks almost serene and tiny, doesn’t it? Yeah, until you grasp the scale of this picture: from left to right it’s well over 400 km (320 miles) across, and that ice floe is still something like 20 km (12 miles) across, having shrunk a bit on its 3000 km journey. A beacon was placed on it last year and you can track its position online. Some fisherman shot some close-up video of the berg, too.

It’s unclear what will happen with this monster icecube. It may present a shipping danger, or even be trouble for offshore oil rigs in the Newfoundland area. Between the radio beacon and satellite images like this, hopefully its position and movement will be tracked well enough to predict where it’s headed and minimize any trouble it might cause.

Image credit: Jeff Schmaltz, MODIS Rapid Response Team at NASA GSFC


Related posts:

- Enormous glacier calves in largest arctic event seen in 48 years
- Dramatic glacial retreat caught by NASA satellite
- Subterranean glaciers on Mars
- The Amazing Cruise: Day 3 (pix of a glacier I took in Alaska)

CATEGORIZED UNDER: Cool stuff, Pretty pictures

Enormous glacier calves in largest Arctic event seen in 48 years

By Phil Plait | August 23, 2010 7:00 am

The NASA Earth-science satellite Earth Observing-1 has returned another amazing picture: the calving of Petermann Glacier off Greenland. The break happened on August 5, and this shot was taken 11 days later:

eo1_petermanglacier

The fjord is to the bottom, and the ice island that broke off is moving to the upper left. The picture is so clear and detailed that the scale is hard to determine by eye, but when you grasp it it’s mind-boggling: that chunk of ice is more than 25 kilometers long. That’s 15 miles.

Having a hard time grokking that? Here’s a picture of New York City to the same scale:
Read More

CATEGORIZED UNDER: Cool stuff, Pretty pictures, Science
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