Vicinity of the Northern Kasei Valles, also showingBahram Vallis and theVedra Valles,Maumee Valles, andMaja Valles. Flow was from bottom left. Map is ~1,600 km (990 mi) wide; the system extends south another 1,200 km (750 mi) toEchus Chasma. | |
Coordinates | 24°36′N65°00′W / 24.6°N 65.0°W /24.6; -65.0 |
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Naming | "Mars" in Japanese |
TheKasei Valles are a giant system ofcanyons inMare Acidalium andLunae Palus quadrangles onMars, centered at 24.6° north latitude and 65.0° west longitude. They are 1,580 km (980 mi) long and were named for the word for "Mars" in Japanese.[1] This is one of the largestoutflow channel systems on Mars.
This huge system is 300 miles wide in some places. In contrast, Earth's Grand Canyon is only 18 miles wide.[2] It is one of the longest continuousoutflow channel systems on Mars. The Kasei Valles system begins inEchus Chasma, nearValles Marineris. It runs initially northward, then turns eastward and appears to empty intoChryse Planitia, not far from whereViking 1 landed. At around 20° north latitude the system splits into two channels, called Kasei Vallis Canyon and North Kasei Channel.[citation needed] These branches recombine at around 63° west longitude, forming a large island between the channels known asSacra Mensa. Some parts of the Kasei Valles are 2–3 km deep.[3]
Like other outflow channels, they were likely carved by liquid water, possibly released by volcanic subsurface heating in theTharsis region, either as a one-time catastrophic event or multiple flooding events over a long time period. Others have proposed that certain landforms were produced by glacial rather than liquid flow.[4]
Three sets of enormous cataracts (dry falls) are present in the area between an "island" feature in the southern channel, Lunae Mensae, and the craterSharonov.[5][6] These cataracts, evidently carved during megaflooding events, have headwalls up to 400 m high[6] and are considerably larger than the largest terrestrial analog,Dry Falls.[5] They may have migrated over 100 km upstream subsequent to their initial formation.[5]