Author Archives: Andreas Muenchow

Manhattan and Petermann Glacier: Physical and Mental Space

Front of Petermann Glacier 2009 from the CCGS Henry Larsen. [Photo Credit: Pete Davis, Oxford University]

Bob Collins writes with wit and eloquence at Minnesota Public Radio about Petermann Glacier and Manhattan:

Why is it always about you, New York?

This week an iceberg “twice the size of Manhattan” broke off from Greenland’s Petermann Glacier.

What else is twice the size of Manhattan? Just about everywhere else. Manhattan is tiny at only 22 square miles. Manhattan isn’t even the size of Woodbury.

You know what’s bigger than the iceberg? Minneapolis. It’s 53 square miles. But “an iceberg that would easily fit into the boundaries of Minneapolis” (and you, too, Saint Paul) doesn’t quite cut it in the drama department.

Why use Manhattan as the measure of size? Because it suggests something is huge that is not, in fact, as huge as we’re led to believe. We think of Manhattan as big because of the size of the buildings there and the number of people there. The iceberg actually would’ve fit nicely into the Bronx. But people don’t think of the Bronx as huge.

This blog, Icy Seas, compares the entire area to the number of Manhattans. But it brings up an important point that a collapsing iceberg the size of Minneapolis obscures: Most of the melting of glaciers is occurring from below.

I agree. Manhattan is tiny, I walked its streets. But do not all numbers and measures contain or evoke emotions? Drudgery is one, drama another. Stay with me for an example: the color red is a wave that is 0.000000645 meters (=645 nanometers or nm) long. What comes to mind, when I talk about reflectances at 645 nm? Nothing or just a blank stare, perhaps? But if I say “RED,” we may engage and argue. Yet 645 nm is more precise than “red,” because there are many shades of red while there are no such shades of 645 nm. Furthermore, red triggers emotions: just ask a Red Sox fan.

Manhattan is a huge place in my mind, just as Bob Collins says it is. For me it is not the height of buildings or the number of people, but it is Manhattan’s tapestry of world cultures, skin colors, styles of clothing, languages, foods, and histories made anew each day. It is all in our minds, it is a symbol. More people can relate to Manhattan better than they can relate to 58 square kilometers. Most people can relate to the color RED with its dramatic emotions, but few can relate to 645 nm with its precise physics. There is beauty in both.

Shades of red and blues … Vincent Van Gough.

Petermann Glacier, Ice Islands, and Changing Climate

Petermann Glacier is a tidewater glacier in the remote north-west of Greenland. The glacier is grounded at about 600-m below sea level. It has calved two large ice islands, a 4-Manhattan sized island in 2010 and a 2-Manhattan sized one in 2012. These losses cover much of the area shown in this 2009 photo:

Eastern wall of Petermann Fjord as seen from CCGS Henry Larsen’s helicopter in August 2009 with the floating ice shelf. Most of the visible ice shelf has been lost during the 2010 and 2012 calving events. [Photo Credit: David Riedel, British Columbia.]

From selected imagery, I created a short movie (0.7 MB) which shows (a) the 2010 calving, (b) the advance of the new front in 2011 and early 2012, and (c) the 2012 calving. The glacier has moved at a rate of about Continue reading

New Petermann Ice Island forming July-16, 2012

This morning Petermann Glacier lost another ice island of a size comparable to what it lost in 2010:

MODIS-Aqua image of July 16, 12:00 UTC of a new ice island forming from Petermann Glacier.

The break-off point has been visible for at least 8 years in MODIS imagery propagating at speeds of 1 km/year towards Nares Strait. The fracture also extended further across the floating ice sheet from the northern towards its southern side.

This event is still evolving, Trudy Wohleben of the Canadian Ice Service noticed it first (as in 2010) after reviewing MODIS imagery. Several people in several countries are monitoring and assessing the situation, but a first estimate of its size is 200 km^2 (3 Manhattans), I will revise this figure as soon as I got my hands on the raw data 120 +/- 5 km^2 or about 2 Manhattans.

The Canadian Coast Guard Ship Henry Larsen is scheduled to travel to Nares Strait (and Petermann Fjord) to recover moorings placed in 2009. These mooring data, if recovered, will contain ocean current, temperature, salinity, and ice thickness data at better than hourly intervals from 2009 through 2012.

UPDATE: For comparison, I here show the 2010 imagery on the same scale using the same processing and colors. There will be more imagery this evening as MODIS-Terra passes over the area closer to nadir (better resolution or sharpness of the images). Furthermore, clouds seem to be disappearing.

The 2010 Petermann Glacier calving event also indicates the crack that broke off this morning as indicated. Note that the entire floating ice shelf moves by about 1 to 1.3 km per year, slightly less than a mile per year. The crack in 2010 is where the 2012 ice island formed.

EDIT: Changed 2012 MODIS-Terra figure which now has the correct (July 16, 2012) date that the data were taken.

Independence Fjord, Peary, and the First Thule Expedition

Independence Day 2012. Independence Fjord 1912. The mapping of northern Greenland.

I am reading 100-year-old travel reports by Danish polar explorers Knud Rasmussen and Peter Freuchen who visited Independence Fjord exactly 100 years ago to resolve a puzzles of Greenland’s geography: Is Peary Land an island or Greenland’s North? It is Greenland, but their detailed report has data I want: glaciers mapped, temperatures recorded, ice described, rocks sampled, musk ox killed. It is all part of an ongoing scientific journey of discovery and writing, but I am getting ahead of my Independence Day and Independence Fjord story:

Map of Greenland as included in the Report of the First Thule Expedition 1912 by Knud Rasmussen also showing contemporary expeditions across the Greenland ice sheet.

The Greenland mapping and early science was done painstakingly via sled dog teams by hardy people and adventurous spirits who had to find and hunt game to avoid death by starvation. Rasmussen, Freuchen, and their Inuit companions Uvdloriaq and Inukitsoq set out over Greenland’s inland ice from Thule on April 19, 1912 with 54 dogs to return 5 months later with only 8 dogs.

Ascent of the Inland ice in April 1912 as the First Thule Expedition starts from Clemens Markham’s Glacier to Independence Fjord. All 4 explorers returned, but only 8 of the 54 dogs did.

This was the First Thule Expedition that was supported by the Thule Trading Post at North Star Bay that Rasmussen and Freuchen had privately established in the fall of 1909. Today it is the location of Thule Air Force Base. My father-in-law served here for a year as a young Airman in the 60ies. It is also where our Nares Strait science party will board the Canadian Coast Guard Ship Henry Larsen Aug.-1, 2012. I am thinking of Peter Freuchen and his Inuit wife Naravana, Knud Rasmussen, and Independence Fjord on this Independence Day.

The Freuchen family on a visit to Denmark: Naravana, Pipaluk, Peter, and Mequsaq [Source: Freuchen, P., 1953: Vagrant Viking. Julian Messner Inc., NY, 312 pp.]

Independence Fjord in the summer of 2007 as seen from Kap Moltke looking south. [Source: web]

Independence Fjord in north-east Greenland was named by Robert E. Peary on America’s birthday 120 years ago on July 4, 1892 when he was the first white person to get there. Prehistoric people of the Independence cultures left artifacts from 3000 years ago. Hunting was good then, too. The 120 year old photograph of Peary shows him standing atop Navy Cliff next to a cairn with two Star Spangled Banners fluttering in the wind. The view eastward is along the 120 mile (200 km) long and 19 miles (30 km) wide Independence Fjord that opens into the Greenland Sea.

Peary at Navy Cliff, Greenland on July 4, 1892 atop Independence Fjord. [Photo Credit: Bowdoin College]

Note left by R.E. Peary on July 5, 1892 at a cairn at Navy Cliff overlooking Independence Fjord which he named here such. The darker pencil at the bottom is Peter Freuchen’s.

Peter Freuchen of the Thule expedition recovered Peary’s note 100 years ago. He then made and left a copy, added his own note, and headed home to Thule, Greenland. Besides checking on Peary the two Danes were also looking for a lost Danish expedition led by Einar Mikkelsen, who in turn was looking to recover the bodies of two Danish explorers of Independence Fjord, Ludvig Mylius-Erichsen and Niels Peter Hoegen-Hagen who had died nearby in 1907. Almost all these explorers have mountains, glaciers, land, and capes named after them or their sponsors, only Independence Fjord is different.

Independence Fjord celebrates the birthday of a young nation, the idea of a painfully evolving democracy, work still in progress. Peary may have made many claims that were not always supported by the evidence he presented, such as claiming to have reached the North Pole. He was no scientist, but a manager driving hard to secure funds, a ruthless self promoter, and autocrat assigning native women to men of his liking. But in this one instance of naming one of Greenland’s grand fjords Independence Fjord, he did good. Recall that this was the time when unelected kings, queens, generals, and dictators were ruling over expanding colonial empires. It was a few years before World War I and its follow-up World War II that caused global devastation to usher in a new set of world powers. The idea of independence is symbolized both in Independence Fjord and Independence Day. Both celebrate the same thing: freedom. There will be fireworks tonight …

P.S.: Some maps

North-East Greenland [Source: web]

MODIS-Terra imagery of Independence Fjord for June 18, 2012. Top panel shows reflectance in the near infra-red (1240 nm) emphasizing land while the bottom panel shows reflectance in the visible red (865 nm) emphasizing ice. The red dot indicates Navy Cliff, the vantage point at the western terminus of Independence Fjord with Academy Glacier to its south-east and Sophie Marie Glacier to its north-west.

Nares Strait 2012 Ice Arch Collapsing (Updated 6/30)

UPDATE-2 6/30:

June-30, 2012 MODIS-Terra view of the collapsing Nares Strait ice arch. The separation occured at the location where the hairline fracture developed 3 days ago. The collapse is propagating upstream to the north as the buttressing support on the western anchor point near Bache Peninsula and Pim Island was removed.

UPDATE-1 6/29:

June-29, 2012 MODIS-Terra view of the collapsing Nares Strait ice arch. The separation occured at the location where the hairline fracture developed 2 days ago.

The most relevant weather information is from Hans Island near 81 N latitude.

ORIGINAL Post (6/28/2012):
The collapse of the ice-arch in southern Nares Strait began June-27, 2012 with development of a small hairline fracture along the western side of the strait off Ellesmere Island, Canada. The fracture connects an isolated area of open water off Bache Peninsula, Canada at 79 N latitude. The front between land-fast ice in the north and the open water in the south has moved slightly southward. It has also lost a visible larger piece of ice that before anchored the bridge at its western connection to land. This motion will open the hairline fracture more, accelerating the collapse of the ice-arch. The missing support of the ice-arch on its western side will collapse the entire ice-arch and the previously land-fast ice of Nares Strait will stream rapidly to the south, I predict, before this weekend.

Updates (including an animation) will be posted daily at http://muenchow.cms.udel.edu/Nares2012/Kane/.

Ice-bridge at southern Nares Strait June-26, 2012 23:30 UTC from MODIS-Terra. There are no hairline fractures yet along the Ellesmere Island side near 79 N latitude. Greenland is on the right (east), Canada on left (west).

Ice-Bridge at southern Nares Strait on June-27, 2012 17:40 UTC from MODIS-Terra. Notice the crack and hairline fractures in the ice along the Ellesmere Island coast near 79 N latitude and 75 W longitude.

This collapse happens each year in the summer, though the timing varies from April for weak and July for strong arches. The arch in 2012 lasted longer than the one in 2011. No or only weak ice-arches formed at this site in 2007, 2008, and 2009, e.g., http://muenchow.cms.udel.edu/MODIS/.

EDIT-1: Same imagery, same gridding, but more focus and detail

MODIS-Terra June-26, 2012 prior to collapse.

MODIS-Terra June-27, 2012 at the onset of collapse. Note the change near the Canada at 79 N latitude where open waters meets the sea ice.

EDIT-2: The moorings we try to recover this summer are to the north of Kane Basin and to the south where Petermann Fjord enters Nares Strait. This map shows it (also notice how badly the coastline of Greenland is surveyed):

June-10, 2012 MODIS-Terra image showing location of moored array that was deployed in Aug. 2009 to be recovered in Aug. 2012.