answer
The earth rotates once every 23 hours, 56 minutes and 4.09053 seconds, called the sidereal period, and its circumference is roughly 40,075 kilometers. Thus, the surface of the earth at the equator moves at a speed of 460 meters per second--or roughly 1,000 miles per hour
Over the past million years, Earth's globally averaged surface temperature has risen and fallen by about 5˚C in ice-age cycles, roughly every 100,000 years or so (Figure 2.1a).
Fundamental right is a citizen's right to travel freely between states
Answer:
When two oceanic plates collide one oceanic plate is eventually subducted under the other. Where one plate slides under the other is referred to as the 'subduction zone'. As the subducting plate descends into the mantle where it is being gradually heated a benioff zone is formed. This benioff zone is a zone of shallow,intermediate and deep focused earthquakes. Some deep focused earthquakes that occur at ocean ocean- collision boundaries can be as deep as 670 kilometres. As the subducted plate descends into the mantle it is gradually heated allowing the formation of magma. The magma that forms is andesitic in composition and begins to form when the subducted plate reaches a depth of 100 kilometres. This andesitic magma is formed from the partial melting of the asthenosphere just above the subduction zone. This partial melting of the subducting plate is due to the loss of water as it descends into the mantle. The andesitic magma is now less dense than the surrounding material so it rises through the crust and erupts to form an arc of volcanoes called an island arc. The distance between the trench and the island arc depends greatly upon where the subducting plate reaches the 100 kilometer depth. If the subduction angle is steep then the distance between the arc and the trench will be short.If the suduction angle is shallow the distance is longer. The main features are indicated in the diagram below. The swell is seen by a bulge in the in the downgoing plate where it is subducted into the mantle.where the plate subducts into the mantle is known as the trench.the forearc ridge contains highly deformed sedimentary and metemorphic rock. The backarc region is located behind the arc and can be compressed or extended.
Explanation:
Faults that have moved in the last 120,000 years are considered likely to move again and are classified as active faults. The evidence of most active faults is that they repeatedly break the earth's surface.
