Split Thumb is a 5,523 ft (1,680 m) glaciated mountain summit located in the Boundary Ranges of the Coast Mountains, in the U.S. state of Alaska.[4] The peak is situated near the southern periphery of the Juneau Icefield, 9 mi (14 km) northeast of Juneau, 2.15 mi (3 km) southeast of Nugget Mountain, and 4 mi (6 km) east of Heintzleman Ridge, on land managed by Tongass National Forest. Split Thumb is surrounded by the Lemon Creek Glacier to the west, and Norris Glacier to east. The Split Thumb Icefall is set on the east aspect of the peak.[5] This peak's descriptive name was published in 1951 by the U.S. Geological Survey.[4] The first ascent of Split Thumb was made July 2, 1954, by a Juneau Icefield Research Project party comprising Edward LaChapelle, Dick Hubley, Carlton Ray, Dr. Conrad Buettner, and Bob Goodwin.[6]
| Split Thumb | |
|---|---|
 Split Thumb, south aspect | |
| Highest point | |
| Elevation | 5,523 ft (1,683 m)[1] |
| Prominence | 923 ft (281 m)[1] |
| Parent peak | Mount Wrather[2] |
| Isolation | 2.15 mi (3.46 km)[1] |
| Coordinates | 58°24′23″N 134°18′44″W / 58.40639°N 134.31222°W[1] |
| Geography | |
  Split Thumb Location in Alaska | |
 | |
| Interactive map of Split Thumb | |
| Country | United States |
| State | Alaska |
| Borough | Juneau |
| Protected area | Tongass National Forest |
| Parent range | Coast Mountains Boundary Ranges Juneau Icefield[1] |
| Topo map | USGS Juneau B-1 |
| Geology | |
| Rock age | Late Cretaceous |
| Rock type | Granitic |
| Volcanic arc/belt | Coast Range Arc |
| Climbing | |
| First ascent | July 2, 1954 |
| Easiest route | class 5.4 Southeast arête[3] |
Climate
editBased on the Köppen climate classification, Split Thumb is located in a subarctic climate zone, with long, cold, snowy winters, and cool summers.[7] Weather systems coming off the Gulf of Alaska are forced upwards by the Coast Mountains (orographic lift), causing heavy precipitation in the form of rainfall and snowfall. Winter temperatures can drop below 0 °F with wind chill factors below −10 °F. The month of July offers the most favorable weather to view or climb Split Thumb.
Gallery
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Looking north at Split Thumb as seen from Observation Peak
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See also
edit
References
edit- ^ a b c d e "Split Thumb, Alaska". Peakbagger.com. Retrieved 2020-03-27.
- ^ "Split Thumb". Bivouac.com. Retrieved 2020-03-27.
- ^ "Split Thumb - 5,523' Alaska". listsofjohn.com. Retrieved 2020-03-27.
- ^ a b "Split Thumb". Geographic Names Information System. United States Geological Survey, United States Department of the Interior. Retrieved 2020-03-27.
- ^ "Split Thumb Icefall". Geographic Names Information System. United States Geological Survey, United States Department of the Interior. Retrieved 2020-03-27.
- ^ "AAC Publications - North America, U.S., Alaska, Split Thumb, Juneau Ice Field".
- ^ Peel, M. C.; Finlayson, B. L.; McMahon, T. A. (2007). "Updated world map of the Köppen−Geiger climate classification". Hydrol. Earth Syst. Sci. 11 (5): 1633. Bibcode:2007HESS...11.1633P. doi:10.5194/hess-11-1633-2007. ISSN 1027-5606.
External links
edit- Split Thumb weather forecast
- Flickr photo: Split Thumb Icefall
- Photo: "Split Thumb"
- Account of first ascent: Americanalpineclub.org
- Climbing Split Thumb: YouTube