Monday, August 9, 2010

Three Times the Size of Manhattan and It FLOATS!

What is over three times the area of Manhattan and floats? It is the tip of the tongue of the Petermann Glacier in Greenland which has just calved off and is moving at anything but a glacial pace into the Arctic Ocean.

About a month ago my family and I were privileged to watch the Margerie Glacier in Canada's Glacier Bay calve [click on photo for larger view]. Our cruise ship patrolled about a quarter mile away from Margerie for over an hour and we got to see the birth of a handful of chunks. It was impressive to see pieces the size of large buildings come crashing down into the water and float away as tiny icebergs. First we'd see the iceberg-to-be start to fall and then, a second or two later, we heard the snap, crackle, and pop! The crew of the Holland-America Ryndam served cups of thick, hot split pea soup on deck to celebrate our visit.

The image shows the tongue of the Petermann Glacier prior to separation (31 July). The animation shows separation (4 August) and later after it had moved a few miles away (7 August). [Click CLICK HERE TO SEE HI-RES ANIMATION]

The images were generated using Synthetic Aperture Radar (SAR) an advanced, computer-intensive technology with which I am familiar due to my work on military avionics. It is sometimes called Side-Looking Radar. An aircraft (or satellite) flies in a straight line, and emits radar pulses to the side. The return signals are recorded in memory storage and processed to generate an image with high precision equivalent to a "lens" the length of the flight segment. (As we all know, in optics, the larger the lens the sharper the images, and the equivalent applies to synthetic-aperture radars as well.)

The Petermann Glacier grows about 1 KM (5/8 mile) every year. The piece that just broke off is about 30 KM (19 miles) long and thus represents about 30 years of growth.

Normally, much smaller pieces break off on a regular basis - as we witnessed at Margerie - but every several years a big one lets loose, the last one in 1991. Close examination shows a crack developing that may open up in perhaps ten years, giving birth to what could be up to an 8 KM (5 mile) long iceberg.

For comparison, the most recent Petermann iceberg is about 30 x 14 KM (~19 x 8 miles) while Manhattan Island in New York City is about 20 x 4 KM (~12 x 2 miles).

Read more about this event and see some wonderful images at Watts Up With That and the European Space Agency.

Of course, this giant glacier calving has been interpreted as further proof of the dangers of Global Warming. As regular readers of this Blog know, I am a lukewarmer-skeptic on human-caused warming. I accept that we have been in a warming period for the past 150 years or more (since the Little Ice Age) and that human activity is responsible for perhaps 10% of that warming, while the remainder is due to natural cycles. (see Atmospheric Science Made Simple, and Is the IPCC Process Scientific? and Explaining Away Climategate - 1 and Explaining Away Climategate - 2.)


Ira Glickstein

8 comments:

joel said...

Ira's description of the calving of a glacier global warming got me thinking about another difference between the way that people view situations and possibly also L/C mind differences. Some people live in the "now" while others live in the "future." Most hopefully live somewhere in between, i.e., in a balanced view. I speak as a person who recognizes that he fails to appreciate the magnificence of the here and now of a huge hunk of ice, because he is imagining the implications for the future. Fortunately, I'm married to a woman who lives in now and keeps me grounded in reality.

It is clear that predicting and planning are part of our evolutionary advancement. Other animals are very limited in their ability in this domain. Some of us don't do anything without a plan B or even plan C. Others don't even have a plan A. Some of us try to optimize everything including gathering groceries in a supermarket. Others stroll around totally unstressed depending on Divine Providence to bring them what they need.

Brian H said...

Joel;
The implications of the calving glacier for the future are zero. It would be like interpreting the death and collapse of a huge old tree as a sign of deforestation. Not to put too fine a point on it, witless.

joel said...

Brian, I used the example of calving and its implications for the future, because Ira brought it up in his initial post. How about calving and its implications for the near future if you're sitting in a row boat 50 yards away snapping pictures? My point is that some people are totally careless and in the moment. Others are completely preoccupied with the future and possible consequences of what they're doing in the "now." So much so, that they fail to enjoy the now. Perhaps there are three groups; those who won't surf because of the risks, those who surf and don't give a damn, those who surf but fail to enjoy the experience to its fullest, because they imagine the surfboard knocking them unconscious, a shark snapping of a leg or a melanoma twenty years down the line.

Ira Glickstein said...

I think, Joel, you have correctly identified the prudent participant group most of us reasonable people belong to, but you have described them (us) way too sharply.

You said: "[the third group, who partake of dangerous activities cautiously] surf but fail to enjoy the experience to its fullest, ..." YES, so far so good. I have to admit us cautious participants enjoy experiences less than your second group who "surf and don't give a damn".

But, I think you went overboard when you described us cautious participant as actively imagining "the surfboard knocking them unconscious, a shark snapping of a leg or a melanoma twenty years down the line."

When I do things that are a bit dangerous, I am not overwhelmed by my fear or caution because I only take prudent risks. For example: (1) Watching the Margerie Glacier calve from a large ship with a professional crew that kept us a quarter mile away from danger (rather than a rowboat yards away), (2) Ziplining with professionals recommended by the cruise line who provided double cables, secure harnesses, padded trees, and well-qualified guides, and (3) Wearing a hat and other sun-protecting clothing to protect against skin cancer when bicycling, being alert to traffic, etc.

Once I take these precautions, I do not actively think about breaking a bone or getting a melanoma down the line.

Ira Glickstein

joel said...

Ira said: But, I think you went overboard when you described us cautious participant as actively imagining "the surfboard knocking them unconscious, a shark snapping of a leg or a melanoma twenty years down the line."

Joel responds: Yes, I was being overly dramatic. On the other hand, I think your ability to put all risks out of mind once you are committed to a course of action is either rare or exaggerated. Athletes wouldn't spend so much time and effort "psyching" themselves up for a challenge, if it were so easy or common to make a decision and then throw away all doubts.

Fear is not the only emotion that interferes with being "in the moment." Greed for example might pull one's mind away from total enjoyment if one is thinking, "This is great. How can I make a buck from this." An entertainment is a "divertissement" in French, or a diversion of the mind. The entertainment quality can be measured by how much it forces you to focus your mind on the current activity to the exclusion of all else. I'm sure that if I were watching the calving of a glacier, my thoughts would be straying to how I could get yet another serving of hot split pea soup and its consequences for my digestion. :^)

Stu Denenberg said...

Buddhism has an interesting take on this: ANY attachment or aversion acts as a preventative to being in the moment. Fear and anger for example are aversions and greed and lust are examples of attachments. Even joy can be an attachment such as noting how great an orgasm your having destroys (or at least tends to decay) the moment. When you are in the moment you are not thinking thoughts at all, you are in a state of equinimity. Being in the Here and Now is not what you think it is.

Ira Glickstein said...

Welcome back Stu - pleased to hear your wise words channeling the Buddha.

I agree that worrying if the calving glacier will swamp the boat or if I can get another cup of hot split pea soup will dilute my enjoyment of "the moment".

Yes, as you say, "When you are in the moment you are not thinking thoughts at all, you are in a state of equanimity."

OK, perhaps we can compromise between Joel and Buddha (:^):

(1) While watching intently and waiting for the glacier to calve (which was 99.99% of the time we spent in Glacier Bay), I will think about the hot pea soup and when the next one will occur and if the slight squirt of water or fall of some ice is the start of the next big calving, etc, ... and,

(2) When the actual calving starts, I will watch intently and listen -the sound is delayed after the visual- and not think about other things, and,

(3) When it is over, I will think about how great the calving was and wondering if we got a good photo of it, etc.

You say "Even joy can be an attachment such as noting how great an orgasm your having destroys (or at least tends to decay) the moment." Indeed!

Ira Glickstein

Stu Denenberg said...

I think scientists and businessfolk are trained to develop plans before entering a course of action; the advantage being that you can't change your plan if you never had one to begin with.

Once you've become enlightened however, most actions require no plan --- as the Zen Masters have said, "Don't think, just Do!" Of course, this is only the experience and the words of Enlightened Beings who cunningly respond, "Don't take my word for it--- see for yourself" so in order to test the hypothesis, one must spend the rest of one's life following a spiritual path that purports to lead eventually to Enlightenment. You would need an infinite amount time to test that hypothesis! Also the close similarity of "Don't think, just Do!" to the Nike slogan is very suspect if you ask me.

And to make matters even more complicated, the Zen Master is quoted as saying, "For over 50 years, I have been selling water down by the river, ho, ho ho."

The only thing I can say for certain is that Life is certainly a Mystery...or as Tracy Ullman has said, "Life is full of surprises ---and I'm getting sick and tired of it!"