HR: 0800h
AN: C51A-1020    [Abstracts]
TI: Evolution Of The Gregoriev Ice Cap (Tien Shan, Central Asia) For 1980-2050 Revealed By Mathematical Modeling
AU: * Nagornov, O
EM: nagornov@yandex.ru
AF: Moscow Engineering Physics Institute (State University), 31 Kashirskoe Shosse, Moscow, 115409 Russian Federation
AU: Konovalov, Y
EM: konovalov@dpt39.mephi.ru
AF: Moscow Engineering Physics Institute (State University), 31 Kashirskoe Shosse, Moscow, 115409 Russian Federation
AU: Mikhalenko, V
EM: vladimir@mikhalenko.ru
AF: Institute of Geography, Russian Academy of Sciences, 29 Staromonetny Pereulok, Moscow, 119017 Russian Federation
AB: We develope two-dimensional flowline model to study an ice flow of the Gregoriev Ice Cap (Tien-Shan, Central Asia). The model, which takes into account the transverse change of glacier width, is tuned by data on measured surface velocity at the glacier front and the mass balance measurements in 1987 and 1988. The ice flow velocity varies from 0 to 3 m/year along glacier flowline. The velocity maximum is shifted from the lowest part toward the middle part of the Gregoriev Ice Cap for the studied period 1980-2050. The flow velocity near the front of glacier is decreased because of two reasons. The first is the negative mass balance that results in thinning of the glacier tongue. The second is the deeper penetration of the cold temperatures from the surface to the bed because of the glacier thinning in its low part. As a result, an internal heating decreases in this part of the glacier and moderates the flow. the seasonal temperature variations moderate/accelerate the horizontal ice flow near the surface. Due to that the additional significant longitudinal stresses arise in places of the surface slope change. These stresses can exceed the compressive/tensile strength and produce crevasses. The calculated changes of the glacier shape show the degradation and decrease of glaciation at the South slope of the Terskey Ala-Tau (Tien Shan).
DE: 9320 Asia
DE: 1827 Glaciology (1863)
DE: 1863 Snow and ice (1827)
DE: 1600 GLOBAL CHANGE (New category)
DE: 1620 Climate dynamics (3309)
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting