FDC-couch

today

8:30 a.m. Audubon Society Field Trip See Event Description

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9 a.m. Arcata Farmers' Market Arcata Plaza

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9:30 a.m. Discovery Walk: Unknown Waterfront See Event Description

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9:30 a.m. Manila Dunes Restoration Manila Community Center

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10 a.m. Manila Dunes Guided Walk Manila Community Center

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10 a.m. Library Book Sale Humboldt County Library

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10 a.m. Dia de los Muertos and Mexican Folk Art Sale Private Eureka home

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10 a.m. Final Arcata Farmer's Market Arcata Farmers' Market (off the plaza)

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11 a.m. Donlin Foreman Dance Workshop Dell'Arte

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2 p.m. Humboldt Coastal Nature Center Draft Trails Plan Walk Stamps House

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5 p.m. Bati Zado and Show Redwood Raks World Dance Studio

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6 p.m. The Tumbleweeds Chapala Cafe

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6 p.m. Ali Chaudhary (jazz duo) Libation

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6:30 p.m. Not Evil, Just Wrong Humboldt Area Foundation

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7 p.m. Guitar Stan (country) Old Town Coffee & Chocolates

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8 p.m. Guitar Orchestra of Barcelona Arkley Center for the Performing Arts

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8 p.m. Stones in His Pockets Arcata Playhouse

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8 p.m. A Christmas Carol North Coast Repertory Theater

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8 p.m. Donna Landry Swing Dance Moose Lodge

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8 p.m. North Coast Wind Ensemble Fulkerson Recital Hall at HSU

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8:30 p.m. The Last Minute Men (international) Cafe Mokka

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9 p.m. Ian McFeron Band (folk rock) Six Rivers Brewery

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9 p.m. The Michael Paul Band WAVE @ blue lake casino

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9 p.m. The Generatorz (classic rock) Central Station Cocktail Lounge

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9 p.m. Taxi Bear River Casino

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9 p.m. VJ Itchie Fingaz Pearl Lounge

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9 p.m. Jack Ruby Presents + Blue Street + Acufunkture (DIY rock) Jambalaya

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9 p.m. 2nd Annual Scorpio Bash The Red Fox Tavern

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10 p.m. Music by DJ Sidelines

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10 p.m. DJ Icy Hot Aunty Mo's Lounge

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10 p.m. Jemimah Puddleduck (rock) Humboldt Brews

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10 p.m. White Manna + Midday Veil + The King Salmon Duo (rock) Jambalaya

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11 p.m. Radio Moscow (psychadelic blues) + Mosquito Bandito (one-man surf/garage) The Alibi Lounge and Restaurant

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previous columns

March 13, 2008

In Formation

The V-formations of honking Aleutian Cackling Geese that decorate our ...

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March 6, 2008

The Ins and Outs of Tides

The Moon's gravity decreases with distance, so it pulls unequally ...

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  • Tsunnami range simulation. Courtesy USGS. Tsunnami range simulation. Courtesy USGS.
  • Tsunami travel times. Diagram by Don Garlick Tsunami travel times. Diagram by Don Garlick
  • Plot of wave height verses water depth. Diagram by Don Garlick. Plot of wave height verses water depth. Diagram by Don Garlick.
  • Graph of tide guage at Sitka, Alaska. Diagram by Don Garlick. Graph of tide guage at Sitka, Alaska. Diagram by Don Garlick.
  • Diagram showing how waves break and tsunamis surge. Diagram by Don Garlick. Diagram showing how waves break and tsunamis surge. Diagram by Don Garlick.
Tsunami Terrors

Tsunami Terrors

By Don Garlick

Understanding the nature of tsunamis could save your life. They are usually caused by large earthquakes, coastal or submarine. You could expect timely warning of a tsunami generated thousands of miles away, but if our local Cascadia Megathrust is the culprit, the violent shaking would be your cue to head for the highest ground reachable within a few minutes.

Tsunami waves have wavelengths of a few hundred kilometers and travel at almost 800 km per hour in deep water. The first image shows a simulation, by the USGS, of waves 4 hours after their creation by the Magnitude 9 Cascadia quake of Jan 26, 1700, dated by Japanese records. The map shows the propagation of such a tsunami at hourly intervals. It would reach Hawaii in five hours. One generated in Hawaii would reach us in five hours.

The plot of wave height verses water depth explains how a wave may be imperceptible at sea but damaging on the coast. Additionally, long-wavelength waves are more likely to surge than to break. A tide gage at Sitka, 1,000 km from the 1964 Alaskan epicenter, reveals the long duration of tsunami waves.

On March 26, at about 10:30 a.m., there will be a test of NOAA's Tsunami Warning System. Visit www.wrh.noaa.gov/eka/misc/tsunamitest.php for more information.

I thank Prof. Lori Dengler for her input.

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