Citation:

tc-11-997-2017

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Abstract:

Rock glaciers are widespread in the Tien Shan. However, rock glaciers in the Chinese part of the Tien Shan have not been systematically investigated for more than two decades. In this study, we propose a new method that combines SAR interferometry and optical images from Google Earth to map active rock glaciers (ARGs) in the Northern Tien Shan (NTS) of China. We compiled an inventory that includes 261 ARGs and quantitative information about their locations, geomorphic parameters, and down-slope velocities. Our inventory shows that most of the ARGs are moraine-derived (69 %) and facing northeast (56 %). The altitude distribution of ARGs in the western NTS is significantly different from those located in the eastern part. The down-slope velocities of the ARGs vary significantly in space, with a maximum of about 114 cm/yr and a mean of about 37 cm/yr. Using the ARG locations as a proxy for the extent of alpine permafrost, our inventory suggests that the lowest altitudinal limit for the presence of permafrost in the NTS is about 2500-2800 m, a range determined by the lowest ARG in the entire inventory and by a statistics-based estimation. The successful application of the proposed method would facilitate effective and robust efforts to map rock glaciers over mountain ranges globally. And this study provides an important dataset to improve mapping and modeling permafrost occurrence in vast western China.

Other version:

Mapping and inventorying active rock glaciers in the northern Tien Shan of China, link to shapefile

Further details:

Outlines of the mapped rock glaciers, link to Google Earth KMZ file

Coverage:

Median Latitude: 43.709585 * Median Longitude: 84.993124 * South-bound Latitude: 42.766300 * West-bound Longitude: 83.209600 * North-bound Latitude: 44.323400 * East-bound Longitude: 87.440400

Minimum ALTITUDE: 2490 m * Maximum ALTITUDE: 3965 m

Event(s):

NTS (Northern Tien Shan) * Latitude Start: 44.400000 * Longitude Start: 82.200000 * Latitude End: 43.000000 * Longitude End: 87.300000 * Location: Tien Shan, China * Method/Device: Satellite remote sensing (SAT)

Comment:

#-9999 denotes the Null value, representing that the rock glacier has the mean coherence lower than 0.3 or the mean velocity smaller than 5 cm/a.

Parameter(s):

#	Name	Short Name	Unit	Principal Investigator	Method/Device	Comment
1	Identification	ID		Liu, Lin		ARG_id
2	LATITUDE	Latitude		Liu, Lin	Satellite SAR interferometry	Geocode – of the central point (degrees)
3	LONGITUDE	Longitude		Liu, Lin	Satellite SAR interferometry	Geocode – of the central point (degrees)
4	ALTITUDE	Altitude	m	Liu, Lin	Satellite SAR interferometry	Geocode – Altitude (above sea level) of the front line point
5	ALTITUDE	Altitude	m	Liu, Lin	Satellite SAR interferometry	Geocode – Altitude (above sea level) of the initial line point
6	Rock glacier area	Rock gl area	m²	Liu, Lin	Satellite SAR interferometry
7	Rock glacier length	Rock gl l	m	Liu, Lin	Satellite SAR interferometry
8	Aspect ratio	Aspect ratio		Liu, Lin	Satellite SAR interferometry
9	Slope	Slope	deg	Liu, Lin	Satellite SAR interferometry
10	Aspect	Aspect	deg	Liu, Lin	Satellite SAR interferometry	Aspect angle of the rock glacier measured clockwise from the North
11	Rock glacier surface velocity	Rock gl urf vel	cm/a	Liu, Lin	Satellite SAR interferometry	The mean value of the surface velocity within the rock glacier
12	Rock glacier surface velocity, uncertainty	Rock gl surf vel unc	cm/a	Liu, Lin	Satellite SAR interferometry
13	Potential incoming solar radiation	PISR	W/m²	Liu, Lin	Satellite SAR interferometry
14	Temperature, air, annual mean	MAAT	°C	Liu, Lin	Satellite SAR interferometry	at the front line point of the rock glacier
15	Permafrost zonation index	PZI		Liu, Lin	Satellite SAR interferometry	at the front line point of the rock glacier
16	Permafrost zonation index	PZI		Liu, Lin	Satellite SAR interferometry	at the initial line point of the rock glacier
17	Identification	ID		Liu, Lin	Satellite SAR interferometry	The interferometric pair used for identifying the rock glacier

License:

Creative Commons Attribution-NonCommercial 3.0 Unported (CC-BY-NC-3.0)

Size:

3391 data points

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