Book Review: We, the Drowned

Posted on June 21, 2012 by | 1 comment

An epic journey often ends at home. Odysseus was sailing home towards his wife and family, Jason and the Argonauts return home to Thessaly with the Golden Fleece, King Arthur’s Knights return to Camelot after they fail or succeed at their Grail Quest, and, in more modern literature, Frodo returns to the Shire. The hero of an epic fights to preserve his home, and is drawn back there after many adventures. Similarly, sailors paint their bodies with reminders of home: names of loved ones, swallows who travel far but always return to the nest, and navigational stars pointing them home.

Appropriately, Carsten Jensen’s novel We, the Drowned centers its epic tales of traveling the seven seas on the place all of the characters at one point call home: the port town of Marstal, Denmark. Spinning tales of adventure spanning more than a century, Jensen draws from the rich history of Marstal, where he grew up, as well as generations of nautical literature.

Told in a series of shorter stories, reading We, the Drowned is more like listening to the bedtime stories of childhood and the legends you hear around the campfire than reading a 700-page tome. The story loosely follows three generations of Marstallers as they are drawn to the magic and adventure of the sea, living their lives at the beck and call of King Neptune.

The tale begins with Laurids Madsen, the sailor who “went up to Heaven and came down again, thanks to his boots,” and who eventually disappears into an Australian port. The story of his son and their generation growing up is fraught with the misery of a sadistic teacher and lost fathers, but Albert, Laurids son, becomes determined to find him. Albert becomes a central focus of the book, representing Marstal’s past, present and future.

The stories range from shrunken heads and selfish traders to brutal wars and sweet romances. These adventures occur wherever the winds blow the sailors of Marstal, including the coasts of Pacific Islands, the Americas, the depths of Africa, and the frigid waters of the Arctic.

We, the Drowned is a fascinating nautical epic, exploring all of the fantastic, wonderful, terrible and awesome faces of the ocean and the people who travel King Neptune’s realm.

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Nares Strait Ice Bridge and Arctic Ice Thickness Change

Posted on June 19, 2012 by | 9 comments

The ice of the Arctic Ocean is rapidly disappearing. This happens every summer, but for the last 30 years there is a little less ice left at the end of each summer than there was the year before. The areas covered by ice are not only shrinking, the ice is also getting thinner, or so many do believe.

To check out such claims, we placed sound systems on the ocean floor of Nares Strait from which to find out how much the thickness of the ice above has changed. We started this in 2003, were told to stop it in 2009, but privately parked our instruments where they would collect data. We must get to check our sound systems and retrieve the private recordings, because otherwise Poseidon will claim our possessions for parking violations. The Canadian Coast Guard Ship Henry Larsen, we hope, will help us to negotiate water and ice to get us deep into Nares Strait as she and her crew did so well in 2006, 2007, and last in 2009.

CCGS Henry Larsen in thick and multi-year ice of Nares Strait in August 2009. View is to the south with Greenland in the background. [Photo Credit: Dr. Helen Johnson]

The ice profiling sonar sounds system before its first deployment in Nares Strait in August 2003 from aboard the USCGC Healy. It measure ice thickness many times each seconds for up to 3 years. View is to the north-west with Ellesmere Island, Canada in the background. Listening in are Jay Simpkins (left), Helen Johnson, and Peter Gamble.

Nares Strait to the west of northern Greenland is one of two major gates for the thickest, the hardest, and the oldest ice to leave the Arctic for the Atlantic Ocean [Fram Strait to the east of Greenland is the other.] This gate is closed at the moment by an arching ice bridge that locks all ice in place. No ice can leave the Arctic via Nares Strait as long as these arches hold. The ice arch acts as a dam that holds back the flood of ice that will come streaming south hard once the dam breaks. And break it will, usually between the end of June and July.

Ice arch in southern Nares Strait as seen by MODIS Terra on June-18, 2012. Greenland is on the right, Canada on the left. The dark blue colors in the bottom-left are open water, yellow are the ice caps of Greenland and Ellesmere Island and lighter shades of blue are warm ice or land. Humboldt Glacier is the on the right-center where Nares Strait is at its widest with Kane Basin at about 80 N latitude.

Nares Strait Jun.-10, 2012 image showing land-fast ice between northern Greenland and Canada as well as the ice arch in the south (bottom left) separating sea ice from open water (North Water). The coastline is indicated as the black line.

The sooner it breaks, the more old ice the Arctic will lose and the better it is for us to get an icebreaker to where must be to recover our instruments and data. The data will tell us if the ice has changed the last 9 years.

I processed and archived maps of Nares Strait satellite images to guide 2003-2012 analyses of how air, water, and ice change from day to day. Ice arches formed as expected during the 2003/04, 2004/05, and 2005/06 winters lasting for about 180-230 days each year. In 2006/07 no ice arch formed, ice streamed freely southward all year, and this certainly contributed to the 2007 record low ice cover. In 2007/08 the arch was in place for only 65 days. In 2009/10, 2010/11, and now 2011/12 ice cover appear normal as the arches formed in December and lasted until July.

We live in exciting times of dramatic change, some to the better and some to the worse. Some of the change is caused by global warming while most is probably not. We do not know for sure, but most of the evidence points towards us people as a major driver of the change we observe in the Arctic and elsewhere. Nevertheless, climate and its change is one grand puzzle that no single scientist, no single discipline, no single country, and no single continent can solve. There are many pieces that all contribute to how and why the Arctic ice changes the way it does. And this includes the ice arches of Nares Strait. There are many mysteries and unresolved physics in what makes these ice arches tick and what makes them blow to bits, but blow they will … watch it, it’s fun, and perfectly natural.

EDIT: This movie shows just how stable the ice arch is at the moment.

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Petermann Ice Islands Stuck in Ice

Posted on June 13, 2012 by | Leave a comment

Several pieces of the Manhattan-sized ice island that broke off Petermann Glacier, Greenland in 2010 arrived, dispersed, and melted off Newfoundland last summer. They provided stunning displays visible to the naked eye from the coast. The Canadian Ice Service just distributed this set of radar images showing 4 pieces that are all grounded and/or stuck in ice. None are moving.

Overview of fragments of Ice Islands that broke off Petermann Glacier, Greenland in 2010 as of June-11, 2012 from RadarSat composites. [Credit: Luc Desjardins, Canadian Ice Service]

In the open ocean ice is moved by winds stressing the ice from above and by ocean currents stressing the ice from below. Typical sea ice varies in thickness from 1-5 meters (3-15 feet) which is much less than the 30-130 meters (90-400 feet) thick ice islands. Winds thus push thick ice islands much less than they do push the thinner sea ice. Thick ice islands are moved by ocean currents, not winds.

This is why oceanographers like myself love these bits of ice islands to bits: they tell us about the ocean below the surface that satellites do not see, but, sadly, all fragments are stuck either to the seafloor in shallow coastal waters or are cemented in place by immobile sea ice that is “land-fast:” Think of it as ice that is glued to land and to each other. This sheet of glued-together ice extends some distance offshore. The distance can be a few yards during a cold winter night in Maine or 100s of miles off Siberia. Offshore islands, rocky outcroppings, or grounded ice islands all anchor land-fast ice by adding local support and thus strength and stability to the immobile land-fast ice.

Too much talk, lets explain this with an image of the largest ice islands, called PII-B1. It is about 4 km wide and 9 km long. I dropped a black dot in its center as it is hard to see where to look in this image. I also show land in grey, open water in blue, and ice in shades of white and yellow:

Land-fast and mobile sea ice off Baffin Island with Petermann Ice Island PII-B1 grounded near the 150 meter isobath (black dot). Thick lines are 100, 200, and 300-m bottom depths. MODIS Terra data at 250-m resolution from June-6, 2012, 15:05 UTC.

There is clearly a 30-km wide band of ice attached to the land with a line of blue water separating it from ice that is mobile and has different signatures. A blue band of ocean has emerged, I speculate, as the result of winds from the south that moved the mobile ice to the north-east (to the right in the image). Neither the land-fast nor the grounded ice island PII-B1 embedded in it moved, so open water appears where there was mobile ice before. This is called a shore lead and I bet there are plenty of seals and whales feasting there now. Note also the arched entrance to Home Bay (bottom left) where loose ice is scattered towards the headland of Henry Kater Peninsula.

As summer is arriving fast in the Arctic, the land-fast ice will disappear, breaking up as the sun and air above and the ocean below weakens the ice by melting. This will expose the thicker ice islands and icebergs to wind-forced storms and waves more violently than it does now. And even those ice island grounded to the bottom of the ocean in shallow water will become free during a time of higher than normal sea level, perhaps during a spring tide, perhaps during strong winds from the north. Then these currently stuck-in-the-ice ice islands will continue their journey south towards Newfoundland and the Atlantic Ocean that they began in 2010 when they were born in northern Greenland.

EDIT: For context I append an earlier RadarSat image from October-18, 2010 when all segments were much closer in space.

Petermann Ice Islands in northern Baffin Bay of Coburg Island, Canada at 76 N latitude on Oct.-18, 2010, about 2 month after they separated from Petermann Glacier, Greenland at 81N latitude. [Credit: Luc Desjardins, Canadian Ice Service]

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Ice Arches and Gothic Cathedrals

Posted on June 11, 2012 by | 6 comments

Soaring towards heaven awash in light, Gothic Cathedrals awed medieval kings, jesters, and peasants alike. Their upward pointing arches allowed walls of stained windows to filter light into these massive buildings when most dwellings from royal castle to decrepit hut were dark, damp, and filthy. While the power of god was both invoked and abused, it was physics and engineering that allowed these cathedrals to scrape the skies. A delicate balance of forces is of the essence to avoid accelerations and collapse.

Arched windows within an arch inside the Cathedral of Reims, France.

Hence it should not surprise that ice arches buttressed by land show similar elegance and stability, but also dramatic collapse. When these ice arches form and collapse is one factor to determine when the Arctic Ocean will be free of ice in summer.

June-10, 2012 ice arch in Nares Strait between northern Greenland and Canada. The arch has been in place since Dec.-8, 2011.

Nares Strait Jun.-10, 2012 image showing land-fast ice between northern Greenland and Canada as well as the ice arch in the south (bottom left) separating sea ice from open water (North Water).

The Nares Strait ice arch forms between December and April most winters. Unlike the medieval cathedrals it consists of blocks of ice. Once in place, the arch shuts down all ice movement. The ocean water under the ice moves undisturbed southward sweeping newly formed ice away. This creates the North-Water polynya, first reported by William Baffin in his ship logs in 1616. The North Water supports wild life for millenia providing food and trading items for people. Even viking remnants from the time the first Gothic Cathedrals were built in Europe were found here: sections of chain mail, iron point blades, cloth, and boat rivets.

I want the ice arch in Nares Strait to collapse as soon as possible so that a Canadian ice breaker can get us to where we like to recover instruments and data that we deployed in 2009. And while I researched the stability of ice arches and studied Moira Dunbar’s 1969 satellite imagery, I came across a wonderful NOVA broadcast on medieval skyscrapers of glass and stone.” PBS stations will show it on Sept.-9, 2012.

Digging a little deeper, I also found a series of Open University podcasts and videos. My favorite 3-minute segment covers lines of thrust where barely connected irregular blocks of wood form a surprisingly stable yet wobbly arching bridge. If you want to build your own arch, then play interactively for fun with the physics of stone arches.

Since I want to understand and predict when the ice arch of Nares Strait collapses, I must understand how medieval architects and engineers designed their Gothic Cathedrals. I will also need understand why some cathedrals are still standing while others collapsed. My icy building blocks in Nares Strait are not as solid as the stones of Reims Cathedral, but unlike the medieval scientists, today we have computers and mathematics to help … as well as more than 800 more years of experience in science and engineering.

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Moira Dunbar, Arctic Exploration, and Women in Science

Posted on June 7, 2012 by | 6 comments

Throughout history, the ocean has been the domain of sea monsters, Neptune and men. The women found in nautical history are portrayed as distractions or a sailor’s connection to land.  Robert Louis Stevenson only wrote one female character in Treasure Island, Jim Hawkins’ mother, who only briefly graces the pages with her presence.  Pirates and sailors alike did not tolerate women on ships except for a captain’s wife, mistress, or daughter.

This attitude towards women in sailing continued even after American women were given the right to vote in 1920. Born 2 years earlier in Scotland, Moira Dunbar was an extraordinary woman fighting for her right to go to sea in the name of science.

Originally from Edinburgh, Dunbar emigrated to Canada in 1947, where she studied ice movement for the Joint Intelligence Bureau of Canada. She later moved to the Defense Research Board in 1952, where she fought notions that a woman couldn’t go to the Arctic on reconnaissance planes of the Royal Canadian Air Force. She co-authored Arctic Canada From the Air with Keith R. Greenaway in 1956. She logged over 600 flight hours and became the first woman to sail as part of a science crew on board a Royal Canadian Navy icebreaker.

The M/V Calanus as seen August 2007 in Iqualuit (formerly Frobisher Bay) on Baffin Island. Moira Dunbar published hydrographic data collected off Baffin Island from this ship in 1958.[Photo Credit: Andreas Muenchow]

Moira Dunbar persisted in breaking through barriers traditionally placed on her gender, blazing a trail for women in science and research. She wasn’t satisfied with standing by idle while her male colleagues went to the Arctic to study, in person, what she was researching, so she made her own way.

Since Dunbar’s entrance into the world of polar science, women have faced fewer challenges entering scientific fields, but are still underrepresented. Men occupied 74% of science and engineering jobs in the United States in 2006 according to a 2011 National Science Foundation (NSF) study. Within the sciences, even fewer women are in physical sciences and engineering.

Even though these statistics may appear daunting to a woman entering the sciences, there is good news: the number of women in science and engineering has been increasing steadily for a long time. From 1979 to 2008, the number of women and minorities as a percentage of full-time, full professors with science and engineering doctorates has more than quadrupled.

Every year, more women enter the sciences and my experience reflects this: entering Macalester College, St. Paul, MN in 2009 as a first-year female physics major, I found not a single woman in the graduating class. In contrast, I can now name at least 5 beside myself. And in such a small major (only 15-20 students), 5 is quite a large number. Women are heading out into the world of science, just as Moira Dunbar did more than 60 years ago. I know many women working on ships in both the Pacific and Atlantic Oceans as skippers, scientists, cooks, and engineers, and I am looking forward to boarding a Canadian Coast Guard Vessel later this summer for some Arctic research myself.

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