GLY Topic 18
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Once a tsunami crosses the entire Pacific it seldom has a height of more than 5 meters
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True
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Studies now indicate a recurrence interval for large Cascadia subduction zone earthquakes of
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400-500 years
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Trees in the Pacific Northwest add ______ rings per year, and are dormant between the months of _________.
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two, August and May
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There are no subduction zones offshore Japan that might create a tsunami generating earthquake
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False
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The best tree ring estimate of the 1700 Cascadian earthquake was from
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a Sitka Spruce root
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Shoreline evidence for past tsunami along Cascadia includes
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All of these
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A published anthology of Japanese earthquakes recorded from 416 AD to 1872 AD includes about how many earthquakes
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greater than 45,000
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During a subduction zone earthquake, the leading edge of the overriding plate is released to ________ while near the shoreline that land ___________:
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Springs up, sinks or subsides
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Most Japanese tsunami originate from earthquakes
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Just offshore Japan
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The data range of the Cascadian earthquake provided by tree ring evidence overlaps the __________ date of the Orphan tsunami, suggesting it was the parent of the tsunami:
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January 26th
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The Pacific Northwest is also under risk from volcano hazards
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True
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Tree ring dating shows that the sunken ghost forests died when
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After the 1699 growing season and before the 1700 growing season
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Cascadia refers to what region of the united states?
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The Pacific Northwest that is east of the Juan de Fuca plate
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Historical records from South America include no reference to a large earthquake along the South Amercican coast during 1700 AD
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True
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A tsunami with no known point of origin is known as:
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An orphan tsunami
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Computer modeling of the Cascadia tsunami requires that it was what magnitude for it to have caused the Japanese Orphan tsunami?
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8.7-9.2
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The height range of the Japanese Orphan tsunami was about how much
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2-5 meters
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What type of plate boundary is offshore the Washington, Oregon, and northern California?
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a subduction zone
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The Cascadian earthquake that caused the Orphan Tsunami occurred after permanent settlement of the region by people of European descent
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False
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The 1700 Orphan tsunami in Japan had a similar height as another created when and where
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Chile, 1960
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Fortunately, there are no significant Cascadia coastal population centers that might be impacted of another tsunami of the magnitude of Orphan Tsunami
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False
