TY - JOUR
T1 - High-resolution subglacial topography around Dome Fuji, Antarctica, based on ground-based radar surveys over 30 years
AU - Tsutaki, Shun
AU - Fujita, Shuji
AU - Kawamura, Kenji
AU - Abe-Ouchi, Ayako
AU - Fukui, Kotaro
AU - Motoyama, Hideaki
AU - Hoshina, Yu
AU - Nakazawa, Fumio
AU - Obase, Takashi
AU - Ohno, Hiroshi
AU - Oyabu, Ikumi
AU - Saito, Fuyuki
AU - Sugiura, Konosuke
AU - Suzuki, Toshitaka
N1 - Publisher Copyright:
© Copyright:
PY - 2022/7/27
Y1 - 2022/7/27
N2 - The retrieval of continuous ice core records of more than 1 Myr is an important challenge in palaeo-climatology. For identifying suitable sites for drilling such ice, knowledge of the subglacial topography and englacial layering is crucial. For this purpose, extensive ground-based ice radar surveys were carried out over Dome Fuji in the East Antarctic plateau during the 2017/18 and 2018/19 austral summers by the Japanese Antarctic Research Expedition, on the basis of ground-based radar surveys conducted over the previous ∼ 30 years. High-gain Yagi antennae were used to improve the antenna beam directivity, thereby significantly decreasing hyperbolic features of unfocused along-track diffraction hyperbolae in the echoes from mountainous ice-bedrock interfaces. We combined the new ice thickness data with the previous ground-based data, recorded since the 1980s, to generate an accurate high-spatial-resolution (up to 0.5 km between survey lines) ice thickness map. This map revealed a complex landscape composed of networks of subglacial valleys and highlands. Based on the new map, we examined the roughness of the ice-bed interface, the bed surface slope, the driving stress of ice and the subglacial hydrological condition. These new products and analyses set substantial constraints on identifying possible locations for new drilling. In addition, our map was compared with a few bed maps compiled by earlier independent efforts based on airborne radar data to examine the difference in features between datasets. Our analysis suggests that widely available bed topography products should be validated with in situ observations where possible.
AB - The retrieval of continuous ice core records of more than 1 Myr is an important challenge in palaeo-climatology. For identifying suitable sites for drilling such ice, knowledge of the subglacial topography and englacial layering is crucial. For this purpose, extensive ground-based ice radar surveys were carried out over Dome Fuji in the East Antarctic plateau during the 2017/18 and 2018/19 austral summers by the Japanese Antarctic Research Expedition, on the basis of ground-based radar surveys conducted over the previous ∼ 30 years. High-gain Yagi antennae were used to improve the antenna beam directivity, thereby significantly decreasing hyperbolic features of unfocused along-track diffraction hyperbolae in the echoes from mountainous ice-bedrock interfaces. We combined the new ice thickness data with the previous ground-based data, recorded since the 1980s, to generate an accurate high-spatial-resolution (up to 0.5 km between survey lines) ice thickness map. This map revealed a complex landscape composed of networks of subglacial valleys and highlands. Based on the new map, we examined the roughness of the ice-bed interface, the bed surface slope, the driving stress of ice and the subglacial hydrological condition. These new products and analyses set substantial constraints on identifying possible locations for new drilling. In addition, our map was compared with a few bed maps compiled by earlier independent efforts based on airborne radar data to examine the difference in features between datasets. Our analysis suggests that widely available bed topography products should be validated with in situ observations where possible.
UR - http://www.scopus.com/inward/record.url?scp=85135154766&partnerID=8YFLogxK
U2 - 10.5194/tc-16-2967-2022
DO - 10.5194/tc-16-2967-2022
M3 - 学術論文
AN - SCOPUS:85135154766
SN - 1994-0416
VL - 16
SP - 2967
EP - 2983
JO - Cryosphere
JF - Cryosphere
IS - 7
ER -