Laboratory Manual for Introductory Geology 4e

EXERCISE 17.12
Effects of Storm Path and Coastal Geography on Hurricane Damage (continued)
(c) The greatest storm surge damage occurs when storm surge piles up in narrow coastal embayments. Several major
cities along the east coast of North America are located in such embayments and, depending on the storm path, are
vulnerable to major damage. Based on your answers to questions (a) and (b) above, sketch the hurricane paths that
would cause the greatest damage to the areas indicated by the red stars below. Note that, as disastrous as Hurricane
Sandy was to New York City, damage would have been much worse if it had made landfall 20 to 30 miles farther north!
Pennsylvania
New York
New
York
City
New
Jersey
Massachusetts
Connecticut
Rhode
Island
Washington,
D.C.
Maryland
Delaware
Virginia
North
Carolina
An earthquake off the northeastern coast of Japan in 2011 generated devastating
tsunamis that traveled across the Pacific Ocean and slammed into low-lying shorelines.
Tsunami waves as high as 25 to 30 feet were reported from coastal cities in
northeastern Japan. Television reports captured the awesome power of the tsunamis,
showing cars, large boats, and even small buildings being carried or smashed
into pieces. FIGURE 17.28 captures some of that power, even without the live action.
Tsunamis travel at approximately 500 mph—about the speed of a jet plane. At
that rate, Japanese coastal cities 60 to 100 miles from the earthquake epicenter had
only a few minutes’ warning—not nearly enough to evacuate to higher ground.
That is why the damage was so severe and the loss of life so great, even though Japan
is the world’s leader in earthquake readiness. Just 8 hours after the tsunamis struck
Japan, and thousands of miles away, a tsunami generated by the Tō hoku earthquake
hit Hawaii and, later still, the northwest coast of the United States. The waves there
were much lower, and damage was trivial compared with that in Japan.
Nations surrounding the Pacific Ocean’s Ring of Fire have cooperated in forming
a tsunami warning network so that some warning can be given to island and
continental coastlines throughout the Pacific basin. Sensors on strategically placed
buoys can track the passage of a tsunami and relay that information to civil defense
workers. FIGURE 17.29 shows estimated travel times for the tsunami generated by
the epicenter of the Tō hoku earthquake. Whereas Japan had little time to prepare,
other places had many hours. Note that the west coast of South America had nearly
a full day to evacuate coastal areas, California and Oregon about 10 hours, and
Honolulu about 8 hours.
17.5 WHEN SHORELINES BECOME DANGEROUS
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