Note: This data set was first published on the 1998 CAPS CD.
The text for this document was taken unchanged from that CD.

See also Description of Data Files.

IPA Global Geocryological Database
Database Information Sheet

Name of data set
Switzerland : Rock Glaciers, Entremont

Content

Position, Type, Morphometry, Orientation, 1995-1997

Details of Investigators

Reynald Delaloye
Institute of Geography
University of Fribourg Pârolles
1700 Fribourg, Switzerland

Sonia Morand
arcalpin
Av. de la Gare 17
CH-1700 Sion, Switzerland

Coverage of Dataset

1. Study location

Central/Western Alps, Valais, Switzerland

2. Geographic extent - Describe the corners of the box representing data coverage

Northwestern latitude : 46- 05' N
Northwestern longitude : 7- 05' E
Southeastern latitude: 45- 51' N
Southeastern longitude: 7- 19' E

3. Period of investigation - Years covered

Inventory of rock glaciers 1995
Geophysics 1995 - 1997

Summary Description

The Entremont area is 300 square-km wide and located in the western part of the Swiss Alps between the Mont-Blanc Massif and the Valaisian Alps, slightly north of the main crest of the alpine range. Altitude varies between 4313 m above see level (a.s.l.) at the top of the Grand-Combin and 714 m a.s.l for the outlet of the valleys system. The geological composition is essentially dominated by metamorphic rocks (gneiss, shale, quartzite), however some sedimentary layers (limestone, dolomite) are inserted.

The mean annual air temperature is about 0-C at 2300 m a.s.l. and annual precipitation among ranges between 1000 and 1500 mm at 2000 m a.s.l. with a maximum value of about 2000 mm on the alpine crest (Grand-St-Bernard pass). Equilibrium line of glaciers is over 3000 m a.s.l. in the north-facing slopes, the timberline is at about 2100 m a.s.l. and permafrost creeping features exist between 2000 and 3000 m a.s.l, what results in a great variety of mountain and morphological landscapes.

Aerial photographs analyses and field morphological observations have been performed during summer 1995 in order to inventory and map (1:25000) 321 well-developed to embryonic rock glaciers and protalus lobes (coexisting features have been separated) of total area 10.4 sq. km. Rock glacier activity classification results from interpretation of both geomorphological and environmental signs. Some geophysics (BTS measurements and DC resistivity soundings) have been performed between 1995 and 1997 on a few rock glaciers in order to confirm the initial interpretation.

Are described in this file:

1. Location (X, Y): Swiss coordinates near the center of the feature.
2. Front elevation (Z): Elevation (m a.s.l.) at the foot of the front (accuracy: 10 m).
3. Length: Maximal distance (m) between front and roots (accuracy: 10 - 20%).
4. Width: Mean width (m) of the feature (accuracy: 10%).
5. Orientation: Global exposition of the rock glacier.
6. Activity: Interpretation by field indicators observation, only in a few cases by geophysics.
7. Surface (ha): Calculated by 1:25'000 numerical mapping (accuracy: 5 - 10%).
8. Origin: Talus or moraine (debris) derived rock glacier
   

Current storage of data :

Hardware :          Diskette
Paper
Software :          GIS - System

Datacenter :

Institute of Geography
University of Fribourg
Pârolles
1700 Fribourg, Switzerland

Are your data at risk of being lost? No

Bibliography

Delaloye, R. and Morand, S. (1997a). Du Val Ferret au Grand-Combin (Alpes Valaisannes): Inventaire des glaciers rocheux et analyse spatiale numerique du pergelisol a l'aide d'un Systeme d'Information Geographique (IDRISI). - Trav. Diplome, Inst. de Geographie, Univ. Fribourg, Suisse, 115 p. + Annexes (in french, not published).

Delaloye, R. and Morand, S. (1997b). Du Val Ferret au Grand-Combin (Alpes Valaisannes): Inventaire des glaciers rocheux et analyse spatiale numerique du pergelisol a l'aide d'un Systeme d'Information Geographique (IDRISI). - Aktuelle Beitraege laufender Projekte zum Thema Permafrost, Arbeitsheft Nr. 19, Versuchsanstalt fuer Wasserbau, Hydrologie und Glaziologie der Eidg. Technischen Hochschule Zuerich, Ed. D. Vonder Muehll, pp. 34-35 (in french).

Delaloye, R. and Morand, S. (1998). Les glaciers rocheux de la region d'Entremont (Alpes Valaisannes): Inventaire et analyse spatiale a l'aide d'un SIG. - Beiträge aus der Gebirgs-Geomorpholgie. Mitteilungen der Versuchsanstalt für Wasserbau, Hydrologie und Glaziologie (VAW) ETH-Zürich 158, 75-86 (in French, with abstract in English).

Keywords

1. Swiss Alps
2. Entremont
3. Rock Glaciers
4. Inventory of Rock Glaciers
5. BTS Measurements
6. DC Resistivity Soundings

Please cite these data as follows:

Delaloye, R. and Morand, S. 1998. Rock glaciers, Entremont, Valais, Switzerland. In: International Permafrost Association, Data and Information Working Group, comp. Circumpolar Active-Layer Permafrost System (CAPS), version 1.0. CD-ROM available from National Snow and Ice Data Center, nsidc@kryos.colorado.edu. Boulder, Colorado: NSIDC, University of Colorado at Boulder.