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| Titel |
Slope deformations in high-mountain regions as observed by InSAR: Examples from the Cordillera Blanca, Peru |
| VerfasserIn |
Holger Frey, Tazio Strozzi, Rafael Caduff, Christian Huggel, Jan Klimes, Vit Vilimek, Andreas Wiesmann, Andreas Kääb, Alejo Cochachin, Stephen Plummer |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250126698
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| Publikation (Nr.) |
 EGU/EGU2016-6455.pdf |
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| Zusammenfassung |
| Steep topography, the world’s highest concentration of tropical glaciers, numerous glacial
lakes and strong seismic activity combined with a densely populated valley bottom in the Rio
Santa basin characterize the Cordillera Blanca in Peru. Besides glacier-related processes, a
variety of landslide types and processes is present outside the glaciated areas, favoured by the
steep terrain, geological conditions, sparse vegetation, intense precipitation, and strong
seismicity. This combination of high hazard potentials and vulnerabilities results in a long list
of natural disasters.
Information on surface displacements is very valuable for early detection of
emerging hazard potentials and their assessment. Interferometric processing of SAR
data (InSAR) provides the possibility to remotely detect different types of surface
displacement processes, also in remote locations where no other monitoring data are
available. This contribution, developed under the ESA-funded S:GLA:MO project
(sglamo.gamma-rs.ch), shows the potential of InSAR products for hazard assessments and
glaciological investigations in high-mountain regions. We present a selection of different
surface displacements as observed in the Cordillera Blanca based on InSAR data:
a landslide zone near the Rampac Grande village, where in 2009 a landslide
caused casualties and property loss;
a landslide at the entry of the Santa Cruz Valley, northern Cordillera Blanca,
where the displacement history could be reconstructed over five years;
surface displacements at the interior moraine slopes surrounding Laguna
Palcacocha, a major glacier lake above the city of Huaraz, which are compared
to and complemented by geophysical investigations in the field;
surface displacements at the moraine damming Laguna Safuna Alta, a glacier
lake in the northern part of the Cordillera Blanca;
glacier velocities across the entire Cordillera Blanca, revealing ice flow velocities
of more than 200 m yr-1 at certain locations at the end of the dry period.
Data archives of spaceborne SAR sensors such as ERS-1/2, ENVISAT, ALOS
PALSAR-1/2, TerraSAR-X, Radarsat-2 and Sentinel-1 provide information reaching back to
the 1990ies, allowing for detection and analysis of both current and past processes.
Environmental conditions in the Peruvian Andes are particularly favourable for InSAR
analyses, with an extended period of mostly cloud-free conditions during austral winter (dry
season), sparse vegetation cover and only very limited snow coverage, factors that in other
regions often limit the potential of this technology.
This contribution shows the potential of InSAR products, providing unique
information on slope deformations and surface displacements as identified as an important
information source for integrative hazard assessments and glaciological investigations in
high-mountain regions. In particular in combination with field investigations this
technology is very powerful, not only for hazard research, but for other types of
applications related to surface displacements and terrain deformations. In regions like the
Cordillera Blanca, where a variety of potentially hazardous and interacting processes are
present, often under conditions beyond historical evidences, such data products
provide invaluable information for hazard assessments, early detection of hazard
potentials, and a basis for prioritization and decision-making by the authorities. |
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