Name and explain the four major earthquake belts of the Earth.
Answers
Circum-Pacific Belt - About 80% of all earthquakes occur in this belt, including the world's most devastating in terms of life and property loss. Mediterranean-Asiatic Belt - Accounts for about 15% of all earthquakes. Intraplate and Spreading Ridge Only about 5% of all earthquakes.
Answer:
Seismic belt, narrow geographic zone on the Earth’s surface along which most earthquake activity occurs. The outermost layer of the Earth (lithosphere) is made up of several large tectonic plates. The edges where these plates move against one another are the location of interplate earthquakes that produce the seismic belts. Island arcs, mountain chains, volcanism, deep ocean troughs, and oceanic ridges are often features of seismic belts. The two major seismic belts are the Circum-Pacific Belt, which surrounds the Pacific Ocean, and the Alpide Belt, which stretches from the Azores through the Mediterranean and Middle East to the Himalayas and Indonesia, where it joins the Circum-Pacific Belt. A purely oceanic seismic belt lies along the mid-Atlantic ridge.
The Ring of Fire (also known as the Rim of Fire or the Circum-Pacific belt) is a major area in the basin of the Pacific Ocean where many earthquakes and volcanic eruptions occur. In a large 40,000 km (25,000 mi) horseshoe shape, it is associated with a nearly continuous series of oceanic trenches, volcanic arcs, and volcanic belts and plate movements. It has 452 volcanoes (more than 75% of the world's active and dormant volcanoes). About 90% of the world's earthquakes and about 81% of the world's largest earthquakes occur along the Ring of Fire. All but three of the world's 25 largest volcanic eruptions of the last 11,700 years occurred at volcanoes in the Ring of Fire. The Ring of Fire is a direct result of plate tectonics: the movement and collisions of lithospheric plates. especially subduction in the northern portion. The western portion is more complex, with a number of smaller tectonic plates in collision with the Pacific Plate from the Mariana Islands, the Philippines, Bougainville, Tonga, and New Zealand.
A lithosphere (Ancient Greek for "rocky" and "sphere") is the rigid, outermost shell of a terrestrial-type planet, or natural satellite, that is defined by its rigid mechanical properties. On Earth, it is composed of the crust and the portion of the upper mantle that behaves elastically on time scales of thousands of years or greater. The outermost shell of a rocky planet, the crust, is defined on the basis of its chemistry and mineralogy. The layer under the lithosphere is known as the asthenosphere.
The Alpide belt or Alpine-Himalayan orogenic belt is a seismic belt and orogenic belt that includes an array of mountain ranges extending for more than 15,000 km along the southern margin of Eurasia, stretching from Java and Sumatra, through the Indochinese Peninsula, the Himalayas and Transhimalayas, the mountains of Iran, Caucasus, Anatolia, the Mediterranean, and out into the Atlantic. It includes, from west to east, the major ranges of the Atlas Mountains, the Alps, the Caucasus Mountains, Alborz, Hindu Kush, Karakoram, and the majestic Himalayas. It is the second most seismically active region in the world, after the circum-Pacific belt (the Ring of Fire), with 17% of the world's largest earthquakes. The Alpide belt is being created by ongoing plate tectonics such as the Alpine orogeny. The belt is the result of Mesozoic-to-Cenozoic-to-recent closure of the Tethys Ocean and process of collision between the northward-moving African, Arabian and Indian plates with the Eurasian plate.