How does the pressure at the triple point compare with the surface atmospheric pressure on Mars?

The triple point almost invariably exceeds the atmospheric pressure on Mars. Only in the deepest fissures, caves and basins does the pressure exceed it slightly. For example, the Hellas basin may often experience about 10 milibars. Even if, in theory,liquid water can exist in some places, pressure is so close to the triple point that water would evaporate in no time.