<span>The two major forces that shape/reshape the earth are internal forces, i.e.volcanoes and earthquakes and external forces, i.e. weather and the ocean, both of which cause erosion. Volcanoes can add landmass but also can destroy land or cause a winter-like state caused by ash in the atmosphere which can block out the sun and possible killing vast amounts of plant and animal life. Earthquakes can change the land by process of subduction where one plate (land surface or ocean bottom) is forced under another. Erosion wears down geologic formations by the actions of wind and water. Over time water can carve valleys or canyons. Ocean water can erode coastlines by the constant beating of waves on the shore. Wind can carry away particles of land and deposit them elsewhere. Wind and weather combined can be a powerful force for reshaping the earth.</span>
