The Science of Sustainability

Producer's Notes: Scary Tsunamis

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The Great Wave off Kanagawa is often mistakenly associated with the Tsunami.

"If a tree falls in a forest and no one is around to hear it, does it make a sound?"

The philosopher George Berkeley posed this philosophical question and a quick internet search found a somewhat scientific answer in an 1894 issue of Scientific American. There they wrote: "Sound is vibration, transmitted to our senses through the mechanism of the ear, and recognized as sound only at our nerve centers. The falling of the tree or any other disturbance will produce vibration of the air. If there be no ears to hear, there will be no sound."

Maybe sometimes vibrations are heard much later, only when the right person is listening.

On January 26, 1700, at about 9:00 p.m. Pacific Standard Time one of the largest earthquakes ever to strike the Pacific Northwest rumbled across the Cascadia Subduction Zone. This massive earthquake sent a giant 33 foot high tsunami crashing onto shore, inundating the quiet coastline. While there is no written account describing the earthquake, tsunami or consequential damage, the devastation was enormous.

So wait. If there was no written record, how can we know the exact time and date when the tsunami struck? How can we know how big it was or what kind of damage it did? It took some digging and an impressive bit of scientific detective work by geologist Brian Atwater. First scientists discovered an unusual layer of sand in a marsh area that left a clue that a wave had struck, taken sand from offshore and brought it far inland. The scientists were able to date this thin sand deposit to around 1700, plus or minus 25 to 50 years. Then through tree-ring dating they were able to narrow that down to within five or ten years. Further study of tree roots narrowed it down even further to winter, 1700. Then investigators went to Japan and checked for evidence of a tsunami during that time. They looked for one which did not have a known earthquake associated with it. These were known as “orphan tsunami." There, in the records from 1700, was a tsunami the struck Japan, a wave that had the right pattern, right size, and was generated at the same place, the Cascadia Subduction Zone all the way on the other side of the Pacific Ocean. January 26, 1700, 9:00 p.m.

Can it happen again. Yes. Are we listening?


Watch the Scary Tsunamis television story online.


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Category: Geology, Physics, Television

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Chris Bauer

About the Author ()

Chris Bauer is a Media Producer for QUEST. Chris has nearly 20 years experience working in broadcast television; producing sports, history, technology, science, environment and adventure related programming. He is a two-time winner of the international Society of Environmental Journalists Award for Outstanding Television Story and has received multiple Northern California Emmy Awards. Some of his Quest stories have been featured in the San Francisco Ocean Film Festival, Jackson Hole Wildlife Film Festival, United Nations Association Film Festival, the BLUE Ocean Film Festival and the Environmental Film Festival in Washington DC. A 5th generation Bay Area resident and a graduate of St. Mary's College of California, his hobbies include canoeing, snowboarding, wood-working and trying to play the ukulele. He and his family live in San Francisco.
  • Chris Bauer

    NOAA Scientists Find Tsunami “Shadow” Visible from Space

    According to a recent news release from the National Oceanic and Atmospheric Administration, scientists have figured out a new way of tracking tsunamis from space. It turns out tsunamis in the open ocean can change sea surface texture in a way that can be measured by satellite-borne radars. Future warning systems may be able to incorporate this to improved detection and forecasting of tsunami intensity and direction on the ocean surface. Hopefully, this could give people a good heads-up to get to higher ground.

    For more information on the emerging technology, log onto NOAA’s site at: http://www.noaanews.noaa.gov/stories2009/20090715_tsunami.html

  • Chris Bauer

    STORY UPDATE: The images of the tsunami hitting Japan this morning are chilling. The Honshu tsunami was generated by a Mw 8.9 earthquake (38.322°N, 142.369°E ), at 05:46 UTC, 130 km (80 miles) E of Sendai, Honshu, Japan (according to the USGS). In approximately 3 hours, the tsunami was first recorded at DART® buoy 32412.

    To learn more about how this tsunami wave ripples across the Pacific, see:
    http://nctr.pmel.noaa.gov/honshu20110311/

  • Chris Bauer

    STORY UPDATE: Steven Ward, a research geophysicist working at the University of California, Santa Cruz's Institute of Geophysics and Planetary Physics, has made some animated simulations of tsunamis. Here is a selection of his work, posted on Bay Citizen, that relates to the impact of a tsunami in Monterey Bay, other places in California, and beyond. See: http://www.baycitizen.org/weather/interactive/videos-tsunami-simulations/