Can δ18O help indicate the causes of recent lake area expansion on the western Tibetan Plateau? A case study from Aweng Co

TY - JOUR

T1 - Can δ18O help indicate the causes of recent lake area expansion on the western Tibetan Plateau? A case study from Aweng Co

AU - Zhang, Y.

AU - Jones, M.

AU - Zhang, J.

AU - McGowan, S.

AU - Metcalfe, S.

PY - 2021

Y1 - 2021

N2 - Glacier-fed lakes on the Tibetan Plateau (TP) have undergone rapid expansions since the late 1990s, concurrent with the changing climate. However, the dominant cause(s) of lake area increases is still debated. To identify the drivers of lake expansion, we studied Aweng Co, a glacier-fed lake in the western TP, where surface area has increased (0.74 km2 year−1) since the late 1970s and most rapidly (0.998 km2 year−1) since the late 1990s. A water balance model was used to clarify the reasons for increased lake water volume, supported by stable isotope hydrology and the δ18O change recorded in recent sediments. Results showed that glacial meltwater probably had the biggest impact on changes in Aweng Co lake level in recent decades, but that precipitation was also an important contributor. Our study shows that δ18O of carbonate (δ18Ocarb) has great potential for indicating source changes of water supply in such lakes, but there is a need to be cautious when interpreting δ18Ocarb due to the influence of multiple hydrological factors, which can change in dominance over time.

AB - Glacier-fed lakes on the Tibetan Plateau (TP) have undergone rapid expansions since the late 1990s, concurrent with the changing climate. However, the dominant cause(s) of lake area increases is still debated. To identify the drivers of lake expansion, we studied Aweng Co, a glacier-fed lake in the western TP, where surface area has increased (0.74 km2 year−1) since the late 1970s and most rapidly (0.998 km2 year−1) since the late 1990s. A water balance model was used to clarify the reasons for increased lake water volume, supported by stable isotope hydrology and the δ18O change recorded in recent sediments. Results showed that glacial meltwater probably had the biggest impact on changes in Aweng Co lake level in recent decades, but that precipitation was also an important contributor. Our study shows that δ18O of carbonate (δ18Ocarb) has great potential for indicating source changes of water supply in such lakes, but there is a need to be cautious when interpreting δ18Ocarb due to the influence of multiple hydrological factors, which can change in dominance over time.

KW - Glacial meltwater

KW - Lake sediment

KW - Oxygen isotope

KW - Water-balance model

U2 - 10.1007/s10933-020-00158-6

DO - 10.1007/s10933-020-00158-6

M3 - Article

SN - 0921-2728

VL - 65

SP - 169

EP - 180

JO - Journal of Paleolimnology

JF - Journal of Paleolimnology

IS - 1

ER -