This blog provides commentary on interesting geological events occurring around the world in the context of my own work. This work is, broadly, geological fluid dynamics. The events that I highlight here are those that resonate with my professional life and ideas, and my goal is to interpret them in the context of ideas I've developed in my research. The blog does not represent any particular research agenda. It is written on a personal basis and does not seek to represent the University of Illinois, where I am a professor of geology and physics. Enjoy Geology in Motion! I would be glad to be alerted to geologic events of interest to post here! I hope that this blog can provide current event materials that will make geology come alive.

Banner image is by Ludie Cochrane..

Susan Kieffer can be contacted at s1kieffer at gmail.com

Thursday, January 20, 2011

The longest surf ride in the world!

Photo of surfers on undular tidal bore, Cook Inlet:
Scott Dickerson/www.SurfAlaska.net
Video is found by scrolling in here.
Thanks to Geology.com for finding this video of surfers catching a tidal bore in Cook Inlet, Alaska.  Wired magazine says that since January 13 it's had nearly 1,200,000 views! Fantastic waves at many scales.

A tidal bore occurs when the normal daily tides travel up a river or narrow inlet against the direction of river flow.  It is not, as commonly believed, a tsunami, and does not resemble a tsunami.  I saw the famous tidal bore in the Bay of Fundy a few years ago. This bore competes with Ungava Bay for the title of the highest tides in the world.  They appear to be tied at 16.8-17 m! During the 12.4 hour tidal period, 115 billion tonnes of water flow in and out of the bay. The size of the waves depends on the strength of the tides and while the one I saw was only a few inches high, the amount of water pouring into the Bay, and its inexorable march upstream, was phenomenal! Well worth the journey to get there.
Tidal bore in Cook Inlet. Photo from NOAA.
Public domain.

Tidal bores range in shape from the beautiful undular form see in the picture above to a breaking wave; the picture to the right shows a stronger tidal bore in Cook Inlet. Surfing on these waves, known as river surfing, has become a popular sport.


Anonymous said...

you misspelled tons

Susan W. Kieffer said...

I spelled it as tonnes, the metric unit for 1000 kilograms, which was given in the original article.