Alba Mons Flows
This THEMIS image captures overlapping lava flows found on the southwest flanks of Alba Mons, Mars (32.23°N, 245.06E). Alba Mons is the broadest volcano on Mars, covering an area approximately 2000km x 3000km, yet is only 6.8 km high (as opposed to Olympus Mons, which is 26 km high). Its slopes are so gentle (0.5°) that you would not realize you were even standing on it. Yet lava flows extend over 1300 km from its summit. This suggests that the lava had very low viscosity.
The long fracture near the bottom of the image is part of a series of fractures that are found around the perimeter of Alba Mons that might have formed during the settling or collapse of the volcano. The depressions within the fracture are collapse pits, suggesting that lava might have flowed through the fracture and formed a lava tube. The pits opened up when the ceiling of the lava tube caved in.
Alba Mons Flows
This THEMIS image captures overlapping lava flows found on the southwest flanks of Alba Mons, Mars (32.23°N, 245.06E). Alba Mons is the broadest volcano on Mars, covering an area approximately 2000km x 3000km, yet is only 6.8 km high (as opposed to Olympus Mons, which is 26 km high). Its slopes are so gentle (0.5°) that you would not realize you were even standing on it. Yet lava flows extend over 1300 km from its summit. This suggests that the lava had very low viscosity.
The long fracture near the bottom of the image is part of a series of fractures that are found around the perimeter of Alba Mons that might have formed during the settling or collapse of the volcano. The depressions within the fracture are collapse pits, suggesting that lava might have flowed through the fracture and formed a lava tube. The pits opened up when the ceiling of the lava tube caved in.