Late Quaternary glacier sensitivity to temperature and precipitation distribution in the Southern Alps of New Zealand

There are no systematic measurements of seasonal snow in the Southern Alps, New Zealand, so little information is available as to its past variability. To rectify this, a conceptual model is developed that calculates seasonal snow deposition, ablation and accumulation. The model is based on daily temperature and precipitation data from long-established climate stations about the Southern Alps. Output is given as daily specific net balance of snow at five elevation bands from 1000 to 2200 m and as total water stored as seasonal snow over several major river catchments. Model output is in general agreement when tested against the few historical observations of snow and is tuned to the long-term water balance. A chronology of seasonal snow is reconstructed from 1931 to 1993. Area-averaged annual maxima average 366 mm. They show no trend, but large inter-annual variability from less than 200 to over 650 mm w.e. Seasonal snow can peak at any time between September and January.

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Simulation of past variability in seasonal snow in the Southern Alps, New Zealand

Annals of Glaciology ◽

10.1017/s0260305500016098 ◽

1995 ◽

Vol 21 ◽

pp. 377-382 ◽

Cited By ~ 12

Author(s):

B.B. Fitzharris ◽

C.E. Garr

Keyword(s):

New Zealand ◽

Southern Alps ◽

Model Output ◽

Total Water ◽

Seasonal Snow ◽

Temperature And Precipitation ◽

Major River ◽

River Catchments ◽

Snow Deposition

There are no systematic measurements of seasonal snow in the Southern Alps, New Zealand, so little information is available as to its past variability. To rectify this, a conceptual model is developed that calculates seasonal snow deposition, ablation and accumulation. The model is based on daily temperature and precipitation data from long-established climate stations about the Southern Alps. Output is given as daily specific net balance of snow at five elevation bands from 1000 to 2200 m and as total water stored as seasonal snow over several major river catchments. Model output is in general agreement when tested against the few historical observations of snow and is tuned to the long-term water balance. A chronology of seasonal snow is reconstructed from 1931 to 1993. Area-averaged annual maxima average 366 mm. They show no trend, but large inter-annual variability from less than 200 to over 650 mm w.e. Seasonal snow can peak at any time between September and January.

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Timing and Extent of Late Quaternary Glaciation in the Ahuriri River Valley, Southern Alps, New Zealand

10.5194/egusphere-egu21-771 ◽

2021 ◽

Author(s):

Levan Tielidze ◽

Shaun Eaves ◽

Kevin Norton ◽

Andrew Mackintosh

Keyword(s):

New Zealand ◽

Large Scale ◽

Late Quaternary ◽

Southern Alps ◽

River Valley ◽

Entire Study ◽

Geomorphological Mapping ◽

Exposure Dating ◽

Quaternary Glaciation ◽

Exposure Ages

Some valleys in South Island, New Zealand already have a number of well-dated glacier records. However, understanding of the precise timing of old glacial events in many valleys still remains poor. For this purpose, the cosmogenic 10Be surface exposure dating technique was used to constrain the timing and extent of late Quaternary glaciation in the Ahuriri River valley, Southern Alps, New Zealand. The 33 10Be surface-exposure ages from two different moraine complexes range from 16.6&#177;0.4 ka to 19.7&#177;0.5 ka suggesting rapid glacier recession (~17 km) during the last deglaciation.Field observation and geomorphological mapping were also used to investigate the extent and drivers of glaciation in this valley. For the final step, we created detail and comprehensive map of the glacial geomorphology in an area covered by palaeo Ahuriri Glacier, in the central Southern Alps. Geomorphological mapping from high-resolution aerial imagery, large scale topographical maps, average resolution DEM, and several field investigations allowed us to produce the 1:38,000 scale map for the entire study site covering an area of about 532 km2.This newly created map along with the new 10Be surface exposure dataset will help us in better understanding of past glacier-climate interactions in the Southern Alps and in the Southern Hemisphere in general.

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