From glacial erosion to the flow of lava, from mudslides to floods, many theories have been proposed to explain the formation of outflow channels on Mars. But after studying the size and shape of the channels, scientists say that they were probably created by huge and sudden floods known as “outburst floods”. Why? Because, our Earth too has had its share of massive flooding events in the past even though they never were on the scale of what seems to have happened on Mars.
Channelled Scablands in the state of Washington, U.S.A, is said to have formed in a similar manner thousands of years ago when an ice dam holding back a glacial lake burst. It repeated over 40 times creating the Scablands we see today with its dry waterfalls, giant ripple marks and streamlined islands. These are flow features similar to the ones found on the beds of Martian outflow channels!
Scientists say that the outburst floods that created outflow channels on Mars may have been triggered by volcanic explosions or impact events. When they fractured the ground, large stores of liquid water trapped underground beneath layers of ice were released. Rather like a Martian fizzy drink can being popped open! As water rushed out, it must have eroded the sides of the cracks, widening them further, and creating the canyons we see on Mars today.
Picture Credit : Google
