Which of the following best describes melting of the mantle at subduction zones that leads to island arc volcanoes?
A. Heat is carried downward with the subducting plate and melts the mantle above the downgoing plate.
B. The subducted plate subsides into the mantle and allows magma from the lower mantle magma ocean to risetoward the surface.
C. Water released from the subducting plate decreases the melting temperature in the mantle above thedowngoing plate to generate magmas from the overlying mantle wedge
Answer: C. Water released from the subducting plate decreases the melting temperature in the mantle above thedowngoing plate to generate magmas from the overlying mantle wedge
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The figure below shows the intensity of an Earthquake in northern California that affected much of the same areas that were damaged by the 1906 earthquake in a very similar manner. Based on this information, ________
A) people should not be allowed to build homes in the intensity VIII regions because the U.S. taxpayer has to pay to rebuild after such an earthquake
B) in general, the current building codes are adequate, but people should be aware of the hazards in this area
C) construction methods are clearly inadequate in the high intensity areas, and all homes in those areas need to be reinforced
D) people who live in the high intensity regions should be required to carry earthquake insurance
Developing countries have increasingly become involved in the integrated global economy primarily due to
A) increased use of vaccinations. B) improvements in sewage and sanitation. C) constructions of dams and irrigation canals. D) increased use of technology.
Why did the Indonesian government support IPM for agriculture in 1986?
A) They were worried about tsunamis. B) Many people were dying of starvation. C) Pesticides were costing money, causing pollution, and decreasing yields. D) It wanted to encourage research into genetically modified crops. E) The country was in a recession.
As reported by the National Weather Service, the heat index
A) relates temperature and relative humidity. B) combines air pressure and temperature in a comfort index. C) gives you an indication of the effect of wind on the skin. D) is generally reported during critical winter months.