Vagn Walfrid Ekman, Swedish Oceanographer, Born (1874)

If you have ever taken a water or bottom sample in a freshwater lake, you owe your success to Vagn Walfrid Ekman, the namesake for the Ekman Water Bottle and Ekman Dredge.

Ekman was born on May 3, 1874, the son of a Swedish oceanographer.  Ekman went to the University of Uppsala to study physics, but ocean science must have been in his DNA—he quickly switched to oceanography.  Oceanography became his life’s work, most of which was performed while he was a professor at the University of Lund in Sweden.

While still a student, he learned about a peculiar behavior of floating icebergs.  Rather than moving in the direction of the prevailing wind, icebergs moved off at an angle.  Presented with this unsolved dilemma, Ekman performed a theoretical analysis that proved an iceberg’s path was the combination of wind, friction of moving water layers and the Coriolis force of the earth’s rotation.  It explained why icebergs moved off in one direction in the northern hemisphere and the opposite in the southern hemisphere.

Vagn Ekman

His understanding of the detailed movements of ocean waters led him to several other discoveries.  He determined the cause of so-called “dead water” in Scandinavian fjords was the resistance of cold water layers from melting glaciers on the surface of the ocean.  He expanded his work with icebergs into a more general treatment of the movement of water at various depths in the ocean, noting and explaining the deflection of currents again as a balance of wind, friction and Coriolis forces.  The phenomenon, which he explained in a 1905 paper, is called the Ekman Spiral in his honor.  He went on to develop full theoretical analyses of wind-blown ocean currents.

But his work as an experimental scientist is what has made him a common name among freshwater biologists.  He was more than just a theoretician—he excelled at field work as well.  His theories relied on having accurate measurements of aquatic phenomena at various depths.  To collect the data, he invented devices that could be lowered to the appropriate depth and then activated from the surface.  The Ekman Dredge works by lowering an open set of jaws to the bottom of a lake on a rope and then sending a heavy weight down the rope that trips a trigger, closing the jaws.  He also invented the Ekman Bottle, which works similarly—a bottle is lowered to the desired depth, is opened by a dropped weight, fills with water, and then is closed by a second dropped weight.  He also invented a device to measure water currents.  All these tools continue in use today, elegant in their simplicity and efficient in their reliability.

I used Ekman Dredges often in my early research, but my most successful use was with a kindergarten class.  I was telling the children about how much life lives in the bottom of a lake, but that we can’t see it because it is below the surface.  I showed them how an Ekman Dredge worked by simulating the lake bottom with sand in a plastic swimming pool.  When a student sent the weight down the line and thus scooped up a big bite of sand, we put it through a sieve.  And out popped wrapped candy bars that I had buried in the sand.

Thank you, Vagn Ekman!

References:

Ichiye, Takashi.  2018.  V. Walfrid Ekman.  Encyclopedia Britannica.com.  Available at:  https://www.britannica.com/biography/V-Walfrid-Ekman.  Accessed May 1, 2018.

Knight, J. D.   Meet the Ocean Explorers:  Vagn Ekman.  Available at:  http://www.seasky.org/ocean-exploration/ocean-explorers-vagn-ekman.html.  Accessed May 1, 2018.

Welander, Pierre.  Ekman, Vagn Walfrid.  Encyclopedia.com.  Available at:  https://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/ekman-vagn-walfrid.  Accessed May 1, 2018.

This Month in Conservation

January 1
NEPA Enacted (1970)
January 2
Bob Marshall Born (1901)
January 3
Canaveral National Seashore Created (1975)
January 4
The Real James Bond Born (1900)
January 5
National Bird Day
January 6
Wild Kingdom First Airs (1963)
January 7
Gerald Durrell Born (1925)
January 8
Alfred Russel Wallace Born (1823)
January 9
Muir Woods National Monument Created (1908)
January 10
National Houseplant Appreciation Day
January 11
Aldo Leopold Born (1887)
January 12
National Trust of England Established (1895)
January 13
MaVynee Betsch, the Beach Lady, Born (1935)
January 14
Martin Holdgate Born (1931)
January 15
British Museum Opened (1795)
January 16
Dian Fossey Born (1932)
January 17
Benjamin Franklin, America’s First Environmentalist, Born (1706)
January 18
White Sands National Monument Created (1933)
January 19
Yul Choi, Korean Environmentalist, Born (1949)
January 19
Acadia National Park Established (1929)
January 20
Penguin Appreciation Day
January 21
The Wilderness Society Founded (1935)
January 22
Iraq Sabotages Kuwaiti Oil Fields (1991)
January 23
Sweden Bans CFCs in Aerosols (1978)
January 24
Baden-Powell Publishes “Scouting for Boys” (1908)
January 25
Badlands National Park Established (1939)
January 26
Benjamin Franklin Disses the Bald Eagle (1784)
January 27
National Geographic Society Incorporated (1888)
January 28
Bermuda Petrel, Thought Extinct for 300 Years, Re-discovered (1951)
January 29
Edward Abbey, author of “Desert Solitaire,” Born (1927)
January 30
England Claims Antarctica (1820)
January 31
Stewart Udall, Secretary of Interior, Born (1920)
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