Science Recorder | Delila James
Buried channels, believed to have been caused by flooding, have been discovered below the surface of Mars. New 3D maps have allowed these channels to be seen for the first time, say scientists from NASA’s Goddard Space Flight Center, the Jet Propulsion Laboratory, the Planetary Science Directorate in the Southwest Research Institute and the Smithsonian Institution. Their findings were reported in the March 7 issue of the journal Science.
Mars is believed to have been a cold and arid place for the past 2.5 billion years, so understanding what caused the flooding that created these channels is important to an understanding of climate change on the Red Planet. The channels lie in an expanse along the equator in a region called Elysium Planitia. This region shows evidence of the youngest volcanic activity on the planet.
“Our findings show that the scale of erosion was previously underestimated and that channel depth was at least twice that of previous approximations,” said Gareth A. Morgan, geologist at the National Air and Space Museum’s Center for Earth and Planetary Studies and lead author on the paper. “The source of the floodwaters suggests they originated from a deep groundwater reservoir and may have been released by local tectonic or volcanic activity. This work demonstrates the importance of orbital sounding radar in understanding how water has shaped the surface of Mars.”
The research team used data from the Shallow Radar (SHARAD) on board the NASA Mars Reconnaisance Orbiter spacecraft to see beneath the surface of the martian plain. Because the Elysium Planitia has seen extensive volcanic activity over the past several hundred million years, evidence of the new found flood channels was buried under thick lava. The use of subsurface mapping allowed researchers to probe beneath the lava to investigate the length and depth of the 620-mile long Marte Vallis channel system and establish that the floods originated from a heretofore buried part of the Cerberus Fossai fracture system.
Because the Marte Vallis channel system has a similar morphology to more ancient martian channel systems, insight into the formation Marte Vallis may help scientists understand how hydrologic activity worked to create the primordial martian landscape.
The size of the flooding that caused the newly discovered channels is estimated to be similar to the ancient mega-flood that created the Channeled Scablands in the Pacific Northwest region of the United States, in eastern Washington.