From: ken.edgett@asu.edu (Ken Edgett)
Subject: More on Olympus Mons
Date: Fri, 23 May 1997 09:02:01 -0700 (MST)
Dear Mars Educators- I had another thought last night regardin the Olympus Mons elevation story.... The article in July '97 ASTRONOMY said that Ascraeus Mons was now considered to be taller than Olympus Mons. I would agree that it's quite likely that the summit of Ascraeus could be slightly higher than that of Olympus Mons. Based on how we recon heights on Earth, that would make Ascraeus the tallest mountain on Mars.... ... However, Olympus is *actually* the taller volcano. Ascraeus could very well have a summit elevation that is higher, but if you look on a topographic map of Mars, you find that the BASE of Ascraeus Mons is at a higher elevation thant the base of Olympus Mons. In the 1991 US Geological Survey topographic maps, Olympus Mons' base is at about 4 km elevation, but Ascraeus' base is at about 9 km elevation... Olympus Mons would still be the TALLEST. In terms of areal extent, there has been some arguement as to which is the biggest-- and I think either Arsia Mons or Alba Patera beat out Olympus on this one (note that Alba is very flat, but very large in diameter. Also note that if you count the flows coming out of the southern flank of Arsia Mons, then Arsia is probably the biggest in terms of area covered). Ken Edgett Arizona Mars K-12 p.s. I still have doubts about the Margaritifer Sinus low elevation, but I am intrigued, nonetheless--- it might help explain some of the features there...