Why is olympus mons so high

Why would such a huge volcano form on Mars but not on Earth? Scientists think that the lower surface gravity of the red planet, combined with higher eruption rates, allowed for the lava on Mars to pile up higher. The presence and absence of tectonic plates could also play an important role in the different kinds of volcanoes. The hot spots of lava under the crust remain in the same location on both planets. On Earth, however, the movement of the crust prevents the steady buildup of lava.

The Hawaiian Islands , for instance, formed as a plate drifted over a hot spot. Each eruption created a small island in a different spot. But Mars has very limited plate movement. Both the hot spot and the crust remain unmoving. When lava flows to the surface, it continues to pile up in a single spot. Instead of a chain of volcanic islands, large volcanoes such as Olympus Mons form. In fact, three other large volcanoes near Olympus Mons are similarly gigantic; if only one of the four volcanoes in the region existed, it would be the tallest feature in the solar system.

But most researchers disagree. UTC Offset:. Picture of the Day Image Galleries. Watch : Mining the Moon for rocket fuel. Queen guitarist Brian May and David Eicher launch new astronomy book. Last chance to join our Costa Rica Star Party! Learn about the Moon in a great new book New book chronicles the space program. Dave's Universe Year of Pluto.

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