The Cerberus Fossae are a series of semi-parallel fissures on Mars formed by faults which pulled the crust apart in the Cerberus region. They are 1235 km across and centered at 11.28 °N and 166.37 °E. Their northernmost latitude is 16.16 °N and their southernmost latitude 6.23 °N. Their easternmost and westernmost longitudes are 174.72 °E and 154.43 °E, respectively. They can be seen in the Elysium quadrangle. Ripples seen at the bottom of the faults are sand blown by the wind. Numerical modeling of the forces in the crust of Mars suggest that the underlying cause for the faulting is the deformation caused by the Tharsis volcanoes to the east. The faults are quite young, cutting through pre-existing features such as the hills of the Tartarus Montes and the lava apron southeast of Elysium Mons. The formation of the fossae was suspected to have released pressurizedunderground water, previously confined by the cryosphere, with flow rates up to 2 × 106 m3s−1, leading to the creation of the Athabasca Valles. Marte Vallis is another channel that was suggested to have formed from water released from Cerberus Fossae. Crater counts suggest this last outflow from the Cerberus Fossae took place about 2 to 10 million years ago. There has been a suggestion such high discharges of water to the surface through these fissures are physically implausible and that lava was the fluid erupted from the Cerberus Fossae. The flood of lava would have had a volume of about 5000 cubic kilometers, quite typical of flood basalt eruptions on Earth. At these high discharges, lava behaved in many ways like a flood of water. It appears to have modestly eroded parts of the Athabasca Valles and then filled the Cerberus Palus basin. The rafted plates of lava in this by temporary lava pond are remarkably similar in appearance to pack ice seen in the North Sea. While some of the cracks are situated at the top of a topographic rise and are surrounded by flow features, indicating they served as volcanic vents, others are on completely flat terrain without flow features, indicating they are simply fractures. The Cerberus Fossae area has been positively identified as the first tectonically active region on Mars, with marsquakes being geolocated there by seismometer measurements from the NASA InSight lander in 2019; this activity was previously suspected on the basis of the trails of dislodged boulders.
