TY - JOUR

T1 - Formation of a large ice depression on Dålk Glacier (Larsemann Hills, East Antarctica) caused by the rapid drainage of an englacial cavity

AU - Boronina, Alina

AU - Popov, Sergey

AU - Pryakhina, Galina

AU - Chetverova, Antonina

AU - Ryzhova, Ekaterina

AU - Grigoreva, Svetlana

N1 - Boronina, A., Popov, S., Pryakhina, G., Chetverova, A., Ryzhova, E., & Grigoreva, S. (2021). Formation of a large ice depression on Dålk Glacier (Larsemann Hills, East Antarctica) caused by the rapid drainage of an englacial cavity. Journal of Glaciology, 1-16. doi:10.1017/jog.2021.58

PY - 2021/12/31

Y1 - 2021/12/31

N2 - In the afternoon of 30 January 2017, a catastrophic outburst flood occurred in the Larsemann Hills (Princess Elizabeth Land, East Antarctica). The rapid drainage of both a thin supraglacial layer of water (near Boulder Lake) and Lake Ledyanoe into the englacial Lake Dålk provoked its overfill and outburst. As a result, a depression of 183 m × 220 m was formed in the place where Lake Dålk was located. This study summarises and clarifies the current state of knowledge on the flood that occurred in 2017. We present a phenomenological model of depression formation. We specify the reasons for the outburst of the system of lakes Boulder, Ledyanoe and Dålk. In addition, we carry out mathematical modelling of the outburst of each of the three lakes and estimate the flood severity. Outburst hydrographs, channel diameters, volume and duration of floods were calculated. Particular simulation results were validated with field data. In conclusion, we give an overview of the new outburst cycle of the lake system, which began in 2020 with the drainage of the lakes Boulder and Ledyanoe, and the new formation of Lake Dålk. Further research is required to improve our understanding of the lake system responses to changing external factors.

AB - In the afternoon of 30 January 2017, a catastrophic outburst flood occurred in the Larsemann Hills (Princess Elizabeth Land, East Antarctica). The rapid drainage of both a thin supraglacial layer of water (near Boulder Lake) and Lake Ledyanoe into the englacial Lake Dålk provoked its overfill and outburst. As a result, a depression of 183 m × 220 m was formed in the place where Lake Dålk was located. This study summarises and clarifies the current state of knowledge on the flood that occurred in 2017. We present a phenomenological model of depression formation. We specify the reasons for the outburst of the system of lakes Boulder, Ledyanoe and Dålk. In addition, we carry out mathematical modelling of the outburst of each of the three lakes and estimate the flood severity. Outburst hydrographs, channel diameters, volume and duration of floods were calculated. Particular simulation results were validated with field data. In conclusion, we give an overview of the new outburst cycle of the lake system, which began in 2020 with the drainage of the lakes Boulder and Ledyanoe, and the new formation of Lake Dålk. Further research is required to improve our understanding of the lake system responses to changing external factors.

KW - Antarctic glaciology

KW - glacier hazards

KW - glacier hydrology

KW - glacier modelling

KW - ground-penetrating radar

KW - SYSTEM

KW - CHANNELIZED SUBGLACIAL DRAINAGE

KW - REGION

KW - INVENTORY

KW - MOVEMENT

KW - LAKE OUTBURST FLOODS

KW - BENEATH

KW - WEST ANTARCTICA

UR - http://www.scopus.com/inward/record.url?scp=85107373046&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/1cd41f42-cd68-39ab-a059-33f2f7c1c42b/

U2 - 10.1017/jog.2021.58

DO - 10.1017/jog.2021.58

M3 - Article

AN - SCOPUS:85107373046

VL - 67

SP - 1121

EP - 1136

JO - Journal of Glaciology

JF - Journal of Glaciology

SN - 0022-1430

IS - 266

M1 - 0022143021000587

ER -