If something has a 10,000-year shelf life, it’s probably full of preservatives.
But not if you’re talking about the Antarctic “Larsen-B†ice shelf that disintegrated in 35 days in 2002. The Larsen-B ice shelf had been a stable mass of mostly solid ice for at least 10,000 years. Pure and untouched except by the Weddell Seals, which are the only mammals that are known to live there year-round.
Weddell Seals keep breathing holes open in the ice all through the winter by chipping away at the ice with their tusks. Suspicious.
Larsen-B had been around since the last ice age 10,000 years ago.
Let’s put the size of this ice shelf into perspective: 656 feet thick and 1,254.83 square miles—for 10,000 years. The equivalent of 1,200 square miles is 770,000 acres, which would be the White Mountains National Park in New Hampshire.
For an urban comparison, the depth of Larsen-B would be like turning Atlanta onto its side. The surface area would be approximately three times the City of Los Angeles. In other words, the size of Rhode Island.
The demise of Larsen-B was most likely caused by long-term thinning underneath the ice shelf as well as short-term surface melting due to global warming. The surface-melting rate has drastically increased over the last few decades.
This rate is accelerated by the billions of people on the planet and their activities. Some claim that this activity is disproportionately American. Could be.
It sure wasn’t the Weddell Seals.
Antarctic temperatures have increased more than 50º F in the last 25 years. The worldwide temperature change has been 35-38º F during the whole post-glacial period.
Does the disintegration of Larsen-B mean that there is a rise in the sea level? Indirectly, yes. The glaciers that were previously “land bound†by Larsen-B have now surged forward, lowering their surfaces. These lower elevations have warmer temperatures, which cause the glaciers to melt into the sea. More loss of ice equals a larger impact on sea level.
To add to this cataclysm is the fact that with increased energy in the atmosphere (global warming), there is a profound increase in storms. Sound like anything we’ve been witnessing lately? These storm surges (with increased water levels) have dramatic effects on low-lying areas, which in turn affects our infrastructures and the precautionary measures we must take to protect from flooding.
The problems this causes for our world are numerous—BUT—there have been some fascinating discoveries of the deep ocean floor under the area that the ice shelf inhabited for so many years.
“How on earth can there be ANY saving grace to this mess?†you ask. I would hardly call it the “upside†to the loss of Larsen-B, but scientists have documented studies of the seabed where the ice shelf sat for 10,000 years. That is such a long time I can’t even get my mind completely around it.
An underwater video study examining a deep glacial trough in the Weddell Sea, where the Larsen-B ice shelf collapsed, has revealed a sunless habitat on the seabed below the near-freezing Antarctic waters. This enormous community of bacteria living on the ocean floor for millennia means that the chances are great for life existence in other places of our galaxy. These bacteria have been growing at a depth of 2,800 feet beneath the surface of the ice.
Weddell Seals are known to dive to over 2000 feet and stay submerged for over an hour. If they know about what is going on down there, they haven’t told us, but it would be a good application for a cold-water crittercam.
The “new†ecosystem that is open to research covers an area of nearly 580,000 square miles of sea floor or, for comparison sake, the entire Sahara Desert. Researchers believe that the energy source for this life is provided by methane from deep underwater vents. Earth’s energy is fed by photosynthesis from the planet’s surface, whereas this seabed ecosystem is a cold-vent community, fed by the chemical energy within the earth. This opportune research is to be continued in early 2006.
It’s another case of the good, bad, and the ugly. A catastrophic event has implications that will greatly impact life as we know it, yet uncover prospective findings for our future as well. Which way does this scale tip in your opinion?
Jan Blair
Remember the 2004 movie, The Day After Tomorrow? It was the blockbuster hit about a climatologist trying to figure out a way to save the world from abrupt global warming. Larsen-B was the subject of this climate-change film, which was based on the novel, The Coming Global Superstorm, by Art Bell and Whitley Strieber. If you haven’t seen the film, you might want to think about downloadingrenting it.
It’s an eye-opener. Like most popular movies it was criticized by many people who sat still through the whole thing, quite a few folks who couldn’t, and everyone else who didn’t see the movie.
sources
Science Daily Magazine
Variety
Those nefarious seals are at it again!
Thanks for the reminder of how our daily lives affect the environment in which we live.
Keep up the great work, Jan, and I hope to see another post from you soon!
~ Willie
Here’s something else to contemplate. In the past as much as half of the antarctic ice shelf has fallen off, raising sea levels as much as 40 feet in 12 hours. It could happen again. Thankfully the odds are against it. So far.
Global warming,prophecy,or Human ignorance to prioritize. The effect and result will still be the same. We keep slowly setting a trap for ourself in order to advance as a species. Another eye-opener by Jan Blair. I look forward to her next posting. Jan, your research and presentations are superb.
Unfortunately this well-written article is based on inaccurate data and interpretation, and thus damages the credibility of serious researchers attempting to educate people about global warming. (For instance, Antarctic temperatures have increased up to 5 degrees, not 50, over the last 25 years). Accurate facts are needed in to win this debate.
The Schmidt comment is an example of the extent to which this can become a problem by making three absurd claims in a single sentence — by definition ice shelf calving cannot cause sea level changes since they float; there isn’t enough water in all the shelves in all the world to cause a 40′ sea level increase, and a 12 hour timeframe would require transverse wave velocities over 1000 mph, which is double the fastest estimates for megatsunami events.
For accurate information on the current and potential impact of global warming on Antarctica try http://www.coolantarctica.com/Antarctica%20fact%20file/science/global_warming.htm
Mr. Palmer, the article you are commenting on states: “The Antarctic Peninsula is particularly sensitive to small rises in the annual average temperature, this has increased about 2.5°C in the region in the last 50 years, this is 2 or 3 times faster than the average in the rest of the world. This makes it an excellent study area.â€
2.5°C converts to 36.5°F . . . a bit more than 5°F, wouldn’t you say?
According to Science Daily Magazine, (http://www.sciencedaily.com/ and enter “Larsen-B ice shelfâ€):
“‘The disintegration of Larsen B is almost certainly a response to human-induced global warming,’ says Queen’s geographer Robert Gilbert, the only Canadian researcher on the international research team. ‘Antarctic temperatures have increased more than 10°C in the last 25 years. By comparison, the world-wide temperature change during the entire post-glacial period has only been 2 — 3°C,’ he adds.â€
The conversion of 10°C is 50°F. I stand by my source.
The obvious confusion has me confused — is anyone carefully reading what the others are writing?
Very well written article. I have only recently become aware of the environmental implications of humankind’s actions and they seem devastating.
Perhaps the aftermath of Katrina will raise public awareness to the issues facing our world and environment.
It would appear this is no longer the cross some birkenstock wearing hippy has to bear but rather the dragon that all of humanity has to slay.
well, damn humans all to hell, huh? or maybe it’s all Bush’s fault? humans are soooo evil. god, how could we be so cruel to this ice. this ice never did anything to us. ugh, i’m getting sick to my stomach even thinking about it! ok, now i hate humans, and i hate g.w. bush. all because of this, something that will take hundreds- no, thousands of years to affect humanity in any measurable amount. screw humans, seals, bush, and ice shelfs.
>
This example of cavalier attitude is the crux of the problems affecting this planet. In the short time that greedy humans have inhabited the earth and within the past hundred years they’ve succeeded in compromising the ozone, polluted oceans, assassinated wildlife, destroyed plant life that could have been meaningful to combat diseases, depleted natural resources, destroyed forests contributing to cleaner air, and grow biologically altered crops that are affecting the future of mankind and the earth. The only thing I hope for is that humanity destroys itself, starting with the good ‘ole USA and China, and if it doesn’t, I hope mother earth takes its revenge.
Maybe I’ll live long enough to see it. If I’m going to die, I want the rest of the human flotsam to go in one felled swoop.
Your mathematics is troubling.
A 2.5 degree change does *not* mean that you convert 2.5 degrees C to 36.5 degrees F. It means a DELTA of 2.5 degrees. For example, changing from zero degrees to 2.5 degrees, which would correspond to changing from 32 degrees F up to 36.5 degrees F, a total of a 4.5 degree change.
Specifically, to calculate the delta, you need to multiply by 9/5.
Thus, a change of 10 degrees C would correspond to a change of 18 degrees F.
Hi Jim. Photos i received. Thanks
[...] The images, many taken from Google Maps, are accompanied by well-written, albeita wee bit panicky in some cases, articles explaining what damage man hath wrought. The top piece today discusses themidwestern city of Martinsville, which is “dealing with a massive drinking water catastrophe that will likely takeyears, plus possibly millions of dollars, to clean up”. So that’s a bummer. Thenthere is a cool (pun!) image of the retreating, er, collapsed, Antarctic”Larsen-B” ice shelf that disintegrated in 35 days in 2002 (pictured). Depressing eh? So, I guess if you take this siteand match it against the earlier Onion post, well, theysort of cancel each other out, humor-wise. Sorry about that. These icons link to social bookmarking sites where readers can share and discover new web pages. [...]