earthquakes and volcanoes

Question 1

ring of fire

Answer 1

The Ring of Fire is a region around much of the rim of the Pacific Ocean where many volcanic eruptions and earthquakes occur. The Ring of Fire is a horseshoe-shaped belt about 40,000 km long and up to about 500 km wide

Question 2

Strike-slip fault

Answer 2

strike-slip fault, also called transcurrent fault, wrench fault, or lateral fault, in geology, a fracture in the rocks of Earth’s crust in which the rock masses slip past one another parallel to the strike, the intersection of a rock surface with the surface or another horizontal plane.

Question 3

Normal fault

Answer 3

Normal, or Dip-slip, faults are inclined fractures where the blocks have mostly shifted vertically. If the rock mass above an inclined fault moves down, the fault is termed normal, whereas if the rock above the fault moves up, the fault is termed a Reverse fault.

Question 4

Reverse fault

Answer 4

In a reverse fault, the block above the fault moves up relative to the block below the fault. This fault motion is caused by compressional forces and results in shortening. … Other names: thrust fault, reverse-slip fault or compressional fault. Examples: Rocky Mountains, Himalayas.

Question 5

P-waves

Answer 5

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A P wave (primary wave or pressure wave) is one of the two main types of elastic body waves, called seismic waves in seismology. P waves travel faster than other seismic waves and hence are the first signal from an earthquake to arrive at any affected location or at a seismograph.

Question 6

s-waves

Answer 6

Secondary waves, or S-waves, are seismic waves produced by an earthquake. … S-waves are lateral waves that move side to side as a sine wave perpendicular to the direction of the wave. They are the second seismic wave to be felt or recorded during an earthquake, after the conveniently named primary wave.

Question 7

epicenter

Answer 7

the point on the earth’s surface vertically above the focus of an earthquake.

Question 8

focus

Answer 8

A deep-focus earthquake in seismology is an earthquake with a hypocenter depth exceeding 300 km. They occur almost exclusively at convergent boundaries in association with subducted oceanic lithosphere. They occur along a dipping tabular zone beneath the subduction zone known as the Wadati–Benioff zone.

Question 9

Richter magnitude scale

Answer 9

The Richter magnitude scale, also known as the local magnitude (M) scale, assigns a number to quantify the amount of seismic energy released by an earthquake. It is a base-10 logarithmic scale. Micro earthquakes, not felt.

Question 10

explosive volcano

Answer 10

In volcanology, an explosive eruption is a volcanic eruption of the most violent type. A notable example is the 1980 eruption of Mount St. Helens

Question 11

nonexplosive volcano

Answer 11

Nonexplosive eruptions are the most common type of volcanic eruptions. These eruptions produce relatively calm flows of lava in huge amounts. B. Vast areas of the Earth’s surface, including much of the sea floor and the Northwestern United States, are covered with lava form nonexplosive eruptions.

Question 12

Krakatoa

Answer 12

Krakatoa, also transcribed Krakatau, is a caldera in the Sunda Strait between the islands of Java and Sumatra in the Indonesian province of Lampung. The caldera is part of a volcanic island group comprising four islands

Question 13

Yellowstone supervolcano

Answer 13

The Yellowstone Caldera, sometimes referred to as the Yellowstone Supervolcano, is a volcanic caldera and supervolcano in Yellowstone National Park in the Western United States. The caldera and most of the park are located in the northwest corner of Wyoming

Question 14

San Andreas fault

Answer 14

The San Andreas Fault is a continental transform fault that extends roughly 1,200 kilometers through California. It forms the tectonic boundary between the Pacific Plate and the North American Plate, and its motion is right-lateral strike-slip.

Question 15

Mid-oceanic ridge

Answer 15

The mid-ocean ridge is a continuous range of undersea volcanic mountains that encircles the globe almost entirely underwater. … It formed and evolves as a result of spreading in Earth’s lithosphere—the crust and upper mantle—at the divergent boundaries between tectonic plates.

Question 16

shield volcano

Answer 16

Shield volcanoes are the largest volcanoes on Earth that actually look like volcanoes (i.e. not counting flood basalt flows). The Hawaiian shield volcanoes are the most famous examples. … Shield volcanoes are the result of high magma supply rates; the lava is hot and little-changed since the time it was generated.

Question 17

cinder cone volcano

Answer 17

A cinder cone is a steep conical hill of loose pyroclastic fragments, such as volcanic clinkers, volcanic ash, or cinder that has been built around a volcanic vent. The pyroclastic fragments are formed by explosive eruptions or lava fountains from a single, typically cylindrical, vent.

Question 18

composite volcano

Answer 18

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Composite cone volcanoes are also called stratovolcanoes. They form when different types of eruptions deposit different materials around the sides of a volcano. Alternating eruptions of volcanic ash and lava cause layers to form. Over time these layers build up. … Helens is an example of a composite cone

Question 19

hot spot

Answer 19

A frequently-used hypothesis suggests that hotspots form over exceptionally hot regions in the mantle, which is the hot, flowing layer of the Earth beneath the crust. Mantle rock in those extra-hot regions is more buoyant than the surrounding rocks, so it rises through the mantle and crust to erupt at the surface.

Question 20

Mt. Vesuvius

Answer 20

Mount Vesuvius is a somma-stratovolcano located on the Gulf of Naples in Campania, Italy, about 9 km east of Naples and a short distance from the shore. It is one of several volcanoes which form the Campanian volcanic arc.