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A, Index Map of the St. Elias Mountains of Alaska and Canada Showing the Glacierized Areas (Index Map Modi- Fied from Field, 1975A)

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A, Index Map of the St. Elias Mountains of Alaska and Canada Showing the Glacierized Areas (Index Map Modi- Fied from Field, 1975A) Figure 100.—A, Index map of the St. Elias Mountains of Alaska and Canada showing the glacierized areas (index map modi- fied from Field, 1975a). B, Enlargement of NOAA Advanced Very High Resolution Radiometer (AVHRR) image mosaic of the St. Elias Mountains in summer 1995. National Oceanic and Atmospheric Administration image from Mike Fleming, USGS, EROS Data Center, Alaska Science Center, Anchorage, Alaska. K122 SATELLITE IMAGE ATLAS OF GLACIERS OF THE WORLD St. Elias Mountains Introduction Much of the St. Elias Mountains, a 750×180-km mountain system, strad- dles the Alaskan-Canadian border, paralleling the coastline of the northern Gulf of Alaska; about two-thirds of the mountain system is located within Alaska (figs. 1, 100). In both Alaska and Canada, this complex system of mountain ranges along their common border is sometimes referred to as the Icefield Ranges. In Canada, the Icefield Ranges extend from the Province of British Columbia into the Yukon Territory. The Alaskan St. Elias Mountains extend northwest from Lynn Canal, Chilkat Inlet, and Chilkat River on the east; to Cross Sound and Icy Strait on the southeast; to the divide between Waxell Ridge and Barkley Ridge and the western end of the Robinson Moun- tains on the southwest; to Juniper Island, the central Bagley Icefield, the eastern wall of the valley of Tana Glacier, and Tana River on the west; and to Chitistone River and White River on the north and northwest. The boundar- ies presented here are different from Orth’s (1967) description. Several of Orth’s descriptions of the limits of adjacent features and the descriptions of the St. Elias Mountains and the Chugach Mountains are contradictory. For instance, he places the Granite Range in the Chugach Mountains yet has its eastern and western sides bounded by St. Elias Mountains features. In this description, the Granite Range is included in the St. Elias Mountains. The highest peak in the Alaskan St. Elias Mountains is Mount St. Elias (fig. 101). Its 5,489-m-high summit, which lies on the U.S.-Canadian border, is located only about 12 km from sea level as of 2004, measured from the now-stable terminus of the tidewater Tyndall Glacier. During most of the 20th century, as Tyndall Glacier retreated, the distance from the summit to sea level has decreased from nearly 60 km to the present 12 km. This ongoing retreat has produced one of the steepest topographic gradients anywhere on Earth. Elsewhere in the Alaskan St. Elias Mountains, Mount Bona (5,005 m), Mount Vancouver (4,785 m), Mount Fairweather (4,663 m), and Mount Hub- bard (4,557 m) all exceed 4,500 m. More than two dozen other peaks have GLACIERS OF ALASKA K123 Figure 101.—Aerial photograph of the sum- mit of Mount St. Elias and environs on 28 July 2001. At 5,489 m, Mount St. Elias is the highest peak in Alaska’s St. Elias Mountains. Photograph by Bruce F. Molnia, U.S. Geological Survey. 137°W elevations greater than 3,300 m. The highest peak, Mount Logan (6,050 m) is F located entirely within Canada (see Ommanney, 2002a, fig. 20). e re b 2 e Glaciers cover about 11,800 km of the Alaskan part of the St. Elias Moun- e C G h l. tains (Post and Meier, 1980, p. 45). Included are parts of the three largest i l k F temperate glaciers in North America: two piedmont outlet glaciers (Ber- a e r t C e hi b lk e ing and Malaspina Glaciers) and one tidewater glacier (Hubbard Glacier). oo e R t R i R v i iv e v e More than 50 glaciers in the St. Elias Mountains have lengths greater than er r r M 8 km. Many mountainous areas and ranges of the Alaskan St. Elias Mountains e ad ier have been given unique names (from east to west): Chilkat Range, Takhin- e Glac sha Mountains, Fairweather Range, Brabazon Range, Granite Range, Rob- inson Mountains, and Icefield Ranges. For ease of description, the St. Elias Mountains are divided into segments: (1) southeastern St. Elias Mountains UNITEDCANADA STATES (from the Lynn Canal and Chilkat Inlet and River to the eastern side of the l. G Takhin on Alsek River); (2) the south-central St. Elias Mountains (from the western LeBlondeau ids Glacier Dav side of the Alsek River to the western side of Yakutat Bay); (3) southwestern Glacier . l L G St. Elias Mountains (from the western side of Yakutat Bay to the western y e C n d i a Bagley Ice Valley, the western Robinson Mountains, and the Bering Lobe); r s n e B Mu c m ir G C l. M e and (4) the northwestern St. Elias Mountains (from the Canadian border at n d Pa a n cif t a i r c G n G G C B long 141°W. to White River, Chitistone River, Tana River, the eastern wall of a l l r u . a ro rr a c ll ou i G ghs Gl. l e l the valley of Tana Glacier, and the southern side of the Bagley Ice Valley). r a c i e r Als ek Gl. Southeastern St. Elias Mountains Segment: From the l . l G G e e l er i Lynn Canal and Chilkat Inlet and River to the Eastern Riv r g a ek e Als g E r Side of the Alsek River a Dry Gl. M au e Bay t Landsat MSS images that cover the southeastern St. Elias Mountain region la P d G n la a c r from Lynn Canal and Chilkat Inlet and River to the eastern side of the Alsek . ie G l r G B a River have the following Path/Row coordinates: 63/19, 64/18, 64/19, 65/19, and s y n i k op 66/18 (fig. 102). These areas are mapped on the USGS Juneau (Alaska-Can- Johns H 59°N l. ada), Skagway (Alaska-Canada), Mount Fairweather (Alaska-Canada), and G GLACIER BAY NATIONAL PARK er th D ea e and PRESERVE Yakutat (Alaska-Canada) 1:250,000-scale topographic maps (appendix A). w e ir s a o F lla att East of the Glacier Bay drainage, the area between the Chilkat River and iio n Lituya Gl. APPROXIMATE SCALE the Canadian border supports more than 100 small glaciers and several larger V a ll 10 0 10 20 30 KILOMETERS ones, some with lengths approaching 15 km. The largest glacier in this region lle y is the 20-km-long Davidson Glacier, located in the Chilkat Range, which has 2 Finger an area of 115 km (Field and Collins, 1975, p. 251). Many of these glaciers Lituya Bay Glacier B r a d were photographed by the IBC early in the 20th century (IBC, 1952) and y G revisited by an AGS expedition led by Field in 1967 (Field and Collins, 1975). la ADMIRALTY ci La Perouse er ISLAND Except for subsequent coverage provided by aerial photography and satel- Glacier lite imagery, these investigations were the last detailed documentation for K124 SATELLITE IMAGE ATLAS OF GLACIERS OF THE WORLD most glaciers in the area. North of the Klehini River, about a dozen unnamed glaciers, all shorter than 3 km, exist on Hiteshitak Mountain, Mount Prinsep, Four Winds Mountain, and Chilkat Peak. The mountains between the Klehini and Tsirku Rivers also support a num- Figure 102.—Annotated Landsat 2 and 3 MSS false-color composite image mosaic ber of small glaciers, several of which have been named. With the excep- of the St. Elias Mountains from Lynn Canal tion of the Little Jarvis Glacier, very limited recent observations have been to the Alsek River, including the glaciers in made of these glaciers. Named glaciers are Jarvis, Little Jarvis, Boundary, Glacier Bay and environs and those of the and Saksaia Glaciers. Unstudied Jarvis Glacier, with a length of more than Fairweather Range. Landsat 2 and 3 MSS 15 km, flows from Canada into Alaska. The terminus region of the glacier images (21670–19195; 19 August 1979; Path appears to be stagnant, and the lowermost few kilometers are covered by 62, Row 19; 30147–19373; 30 July 1978; moraine. The debris-covered terminus lies about a kilometer from a moraine, Path 64, Row 18; 2952–19124; 31 August which represents a former maximum position, perhaps its “Little Ice Age” 1977; Path 64, Row 19; 21314–19295; 28 maximum. Little Jarvis Glacier, with a length of 3.2 km, is one of the glaciers August 1978; Path 66, Row 18) are from surveyed by the AGS in 1957–58 (see fig. 35) and resurveyed by a University U.S. Geological Survey, EROS Data Center, of Alaska Fairbanks team in 1995 (Sapiano and others, 1998). In the 38 years Sioux Falls, S. Dak. between surveys, the terminus retreated about 190 m, an average of about 137°W F e re b e e C G h l. i l k F a e r t C e hi b lk e oo e R t R i R v i iv e v e er r r M e a er de Glaci UNITEDCANADA STATES l. G Takhin on LeBlondeau ids Glacier Dav Glacier . l L G y e C n d i a r s n e B Mu c m ir G C l. M e d Pa n a n cif t a i r c G n G G C B a l l r u .
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