February 22, 2012
The Red Planet Experiences ‘Marsquakes’
University of London researchers report they have found evidence that Mars experiences "marsquakes" in the same way Earth does with an earthquake.
The researchers said the existence of marsquakes is an indication that conditions on Mars could include liquid water.
The team from the University of London used High Resolution Imaging Science Experiment (HiRISE) imagery to examine a fault system known as Cerberus Fossae.
They analyzed the way boulders had fallen and rolled during avalanches, and found that avalanches are likely to have been caused by ground-shaking associated with marsquakes.
“The HiRISE imagery showed us boulders in the size range of 2-20 meters, that had fallen from cliffs during rock avalanches," Dr Gerald Roberts, who led the study, said in a press release.
"What´s more, both the size of the boulders and the frequency of the boulder falls decreased from a central point along the Cerberus Fossae fault system over a distance of approximately 100 kilometers."
The researchers compared the pattern of boulder falls, and the faulting of the surface of Mars, with those seen in central Italy after a 6.3 magnitude earthquake struck in 2009.
They found that the marsquake was likely to have a magnitude greater than 7.0 due to the 124 miles across area of displaced boulders.
By analyzing the tracks that the falling boulders left on the martian surface, the team determined that the marsquake appears to have been recent because martian winds had not erased the boulder tracks.
This discovery could be significant in searching for life on Mars, because if the faults along the Cerberus Fossae region are active, and the quakes are driven by subterranean volcanism, the energy provided in the form of heat from the igneous dikes might melt ice, creating liquid water.
“It is this link between life, volcanism and active faulting that makes the boulder data we have collected so intriguing," Roberts said in a press release.
The team's findings will be published in February 23 edition of the Journal of Geophysical Research Planets.
Image Caption: This small fossa segment cuts the channel of Athabasca Valles, and post-dates the youngest of Mars' outflow channels. A "fossa" is a cavity or depression. Floods of water and lava are thought to have emanated from the larger fossae nearby, perhaps forming the Athabasca channel and later filling it with lava. Comparison with the larger fossa segments at the Athabasca Valles head may reveal whether this will be a source of a future flood. Credits: NASA/JPL/University of Arizona
On the Net: