Related topics: quake · earth · earthquake · geologists · earth sciences

Strong 7.2 quake rocks Papua New Guinea

A powerful but deep 7.2-magnitude earthquake rocked Papua New Guinea on Tuesday, officials said, cutting power and knocking items off shelves though there were no immediate reports of serious damage.

How did the moon end up where it is?

Nearly 50 years since man first walked on the moon, the human race is once more pushing forward with attempts to land on the Earth's satellite. This year alone, China has landed a robotic spacecraft on the far side of the ...

Nepal expedition to remeasure height of Everest: Officials

Nepal is sending a team of government-appointed climbers up Mount Everest to remeasure its height, officials said Monday, hoping to quash persistent speculation that the world's tallest mountain has shrunk.

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Plate tectonics

Plate tectonics (from the Greek τέκτων; tektōn, meaning "builder" or "mason") describes the large scale motions of Earth's lithosphere. The theory encompasses the older concepts of continental drift, developed during the first decades of the 20th century by Alfred Wegener, and seafloor spreading, understood during the 1960s.

The lithosphere is broken up into what are called tectonic plates. In the case of Earth, there are currently eight major and many minor plates (see list below). The lithospheric plates ride on the asthenosphere. These plates move in relation to one another at one of three types of plate boundaries: convergent, or collisional boundaries; divergent boundaries, also called spreading centers; and transform boundaries. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along plate boundaries. The lateral movement of the plates is typically at speeds of 50–100 mm annually.

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