Chapter 5 Quiz
In the Pacific Northwest, stresses are transmitted upward from the subducting plates, forming strike-slip faults that rupture he surface, as in Seattle.
True
In the central United States, ancient rift valleys remain from failed spreading centers and these ancient rift today are zones of weakness whose faults can be reactivated due to long-distance effects of Atlantic Plate Spreading and Pacific Plate collision.
True
The 1994 Northridge event was similar to the 1971 San Fernando earthquake in magnitude, number of people killed, and type of faulting.
True
The New Madrid, Missouri, 1811-1812 earthquakes have never been equaled in the history of the United States for the number of closely-spaced, large seisms and for the size of the felt area.
True
The New Madrid, Missouri, 1811-1812 earthquakes were felt from Canada to the Gulf of Mexico and from the Rocky Mountains to the Atlantic seaboard, where clocks stopped, bell rang, and plaster cracked.
True
The epicenters of the larger New Madrid, Missouri, earthquakes line up along the Missippi River Valley, possibly because of an ancient rift valley, known as the Reelfoot Rift, formed about 550 million years ago.
True
When rock heats and liquefies into magma its volume ____.
expands, and neighboring brittle rock must fracture and move out of the way
Earthquakes in Hawaii are mostly related to ____.
movement of volcanic magma beneath the ground
Which of the following states has the highest earthquake risk?
Arkansas
As much as 20% of the relative motion between the Pacific and North American Plates may be accommodated by the extensional stretching of the Basin and Range province, leaving numerous north-oriented mountain ranges separated by down-dropped, sediment-filled basins.
False
Earthquakes below Kilauea volcano are dominantly deep evets in the mantle.
False
Historic earthquakes in the Rio Grande Rift area have had only small to moderate magnitudes, but the continental lithosphere continues to comress and shorten, thus presenting a real hazard for large earthquakes.
False
In the last 30 million years, the region between the eastern Sirra Nevada in California and the Wasatch Mountain front in central Utah has contracted in an east-west direction, so Nevada is now half of its former width.
False
The duration of shaking in 1985 in Mexico City was decreased due to seismic energy being trapped within the soft sediments.
False
The 17 January 1994 Northridge earthquake in Los Angeles was generated on a ____ thrust fault.
blind
At Hebgen Lake in 1959 an earthquake larger than magnitude 7 greatly affected ____.
Yellowstone National Park
