6th Grade Study Guide- Volcanoes and earthquakes
Answers
Vocabulary-
P wave
S wave
L wave
Shield cone
Cinder cone
Composite cone
Lave
Magma
Pyroclastic
Focus
Epicenter
Concepts-
1. The crater is at the very top, and the vent is a tunnel that comes out on the side. The magma chamber is the cave inside the volcano.
2. A crater is the mouth at the top of the volcano. A caldera is the empty shell inside the volcano after all the magma and debris have been ejected.
3. Lava flow- red hot molten rock that flows out from the volcano.
Pyroclastic flow- deadly hot rock, ash and gases that explode out at high rates of speed.
4. Examples of volcanoes:
- Pyroclastic- Mount Tungurahua, Mount St. Helens, Mount Vesuvius
- Lava flow- Mount Kiluaea
5. Composite cone: symmetrical shape, alternating layers of ash and hardened lava.
Cinder cone: small cone made of ash, lava, and cinders.
Shield cone: broad volcano with gentle slopes made of hardened lava.
6. The focus is an earthquake’s point of origin, located deep within the earth.
The epicenter is the point on the earth’s crust directly above the focus.
7. The instrument that measures earthquakes is a seismograph. Three locations are needed to pinpoint an earthquake’s epicenter.
8. P wave (primary wave) Fastest wave in an earthquake. Has a push & pull motion.
S wave (secondary wave). Next slowest wave. Has a side to side motion.
L wave (Love wave). Slowest wave. Has a motion like an ocean wave.
9. The Richter scale is used to rate the magnitude of an earthquake. A magnitude lower than 5 is not usually felt by most people. A magnitude greater than 6.5 causes damage to buildings. A magnitude of 10 is the absolute highest on the scale.
10. The major zone of activity is the Ring of Fire. Three areas of major activity are Japan, California, and Hawaii.