Changes in ground deformation prior to and following a large urban landslide in La Paz, Bolivia, revealed by advanced InSAR
<p>We characterize and compare creep preceding and following the complex 2011 Pampahasi landslide (<span class="inline-formula">∼40</span> Mm<span class="inline-formula"><sup>3</sup>±50</span> %) in the city of La Pa...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2019-03-01
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| Series: | Natural Hazards and Earth System Sciences |
| Online Access: | https://www.nat-hazards-earth-syst-sci.net/19/679/2019/nhess-19-679-2019.pdf |
| _version_ | 1811296838382256128 |
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| author | N. J. Roberts B. T. Rabus J. J. Clague R. L. Hermanns R. L. Hermanns M.-A. Guzmán E. Minaya |
| author_facet | N. J. Roberts B. T. Rabus J. J. Clague R. L. Hermanns R. L. Hermanns M.-A. Guzmán E. Minaya |
| author_sort | N. J. Roberts |
| collection | DOAJ |
| description | <p>We characterize and compare creep preceding and following
the complex 2011 Pampahasi landslide (<span class="inline-formula">∼40</span> Mm<span class="inline-formula"><sup>3</sup>±50</span> %) in the city of La Paz, Bolivia, using spaceborne radar
interferometry (InSAR) that combines displacement records from both
distributed and point scatterers. The failure remobilized deposits of an
ancient complex landslide in weakly cemented, predominantly fine-grained
sediments and affected <span class="inline-formula">∼1.5</span> km<span class="inline-formula"><sup>2</sup></span> of suburban development.
During the 30 months preceding failure, about half of the toe area was
creeping at 3–8 cm a<span class="inline-formula"><sup>−1</sup></span>
and localized parts of the scarp area showed
displacements of up to 14 cm a<span class="inline-formula"><sup>−1</sup></span>. Changes in deformation in the 10 months
following the landslide demonstrate an increase in slope activity and
indicate that stress redistribution resulting from the discrete failure
decreased stability of parts of the slope. During that period, most of the
landslide toe and areas near the head scarp accelerated, respectively, to
4–14 and 14 cm a<span class="inline-formula"><sup>−1</sup></span>. The extent of deformation increased to cover most, or
probably all, of the 2011 landslide as well as adjacent parts of the slope
and plateau above. The InSAR-measured displacement patterns, supplemented by
field observations and optical satellite images, reveal complex slope
activity; kinematically complex, steady-state creep along pre-existing
sliding surfaces accelerated in response to heavy rainfall, after which
slightly faster and expanded steady creeping was re-established. This case
study demonstrates that high-quality ground-surface motion fields derived
using spaceborne InSAR can help to characterize creep mechanisms, quantify
spatial and temporal patterns of slope activity, and identify isolated
small-scale instabilities; such details are especially useful where
knowledge of landslide extent and activity is limited. Characterizing slope
activity before, during, and after the 2011 Pampahasi landslide is
particularly important for understanding landslide hazard in La Paz, half of
which is underlain by similar large paleolandslides.</p> |
| first_indexed | 2024-04-13T05:55:12Z |
| format | Article |
| id | doaj.art-c56ffe436d9e4602ad0227430c0f62d0 |
| institution | Directory Open Access Journal |
| issn | 1561-8633 1684-9981 |
| language | English |
| last_indexed | 2024-04-13T05:55:12Z |
| publishDate | 2019-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Natural Hazards and Earth System Sciences |
| spelling | doaj.art-c56ffe436d9e4602ad0227430c0f62d02022-12-22T02:59:39ZengCopernicus PublicationsNatural Hazards and Earth System Sciences1561-86331684-99812019-03-011967969610.5194/nhess-19-679-2019Changes in ground deformation prior to and following a large urban landslide in La Paz, Bolivia, revealed by advanced InSARN. J. Roberts0B. T. Rabus1J. J. Clague2R. L. Hermanns3R. L. Hermanns4M.-A. Guzmán5E. Minaya6Department of Earth Sciences, Simon Fraser University, 8888 University Drive, Burnaby, V5A 1S6, CanadaSchool of Engineering Science, Simon Fraser University, 8888 University Drive, Burnaby, V5A 1S6, CanadaDepartment of Earth Sciences, Simon Fraser University, 8888 University Drive, Burnaby, V5A 1S6, CanadaGeological Survey of Norway, P.O. Box 6315 Sluppen, Trondheim, 7490, NorwayDepartment of Geoscience and Petroleum, Norwegian University of Science and Technology, Trondheim, 7491, NorwayInstituto de Investigaciones Geológicas, Universidad Mayor de San Andrés, Pabellon 3, Campus Universitario Cota Cota, La Paz, 35140, BoliviaObservatorio San Calixto, Indaburo 944, La Paz, 12656, Bolivia<p>We characterize and compare creep preceding and following the complex 2011 Pampahasi landslide (<span class="inline-formula">∼40</span> Mm<span class="inline-formula"><sup>3</sup>±50</span> %) in the city of La Paz, Bolivia, using spaceborne radar interferometry (InSAR) that combines displacement records from both distributed and point scatterers. The failure remobilized deposits of an ancient complex landslide in weakly cemented, predominantly fine-grained sediments and affected <span class="inline-formula">∼1.5</span> km<span class="inline-formula"><sup>2</sup></span> of suburban development. During the 30 months preceding failure, about half of the toe area was creeping at 3–8 cm a<span class="inline-formula"><sup>−1</sup></span> and localized parts of the scarp area showed displacements of up to 14 cm a<span class="inline-formula"><sup>−1</sup></span>. Changes in deformation in the 10 months following the landslide demonstrate an increase in slope activity and indicate that stress redistribution resulting from the discrete failure decreased stability of parts of the slope. During that period, most of the landslide toe and areas near the head scarp accelerated, respectively, to 4–14 and 14 cm a<span class="inline-formula"><sup>−1</sup></span>. The extent of deformation increased to cover most, or probably all, of the 2011 landslide as well as adjacent parts of the slope and plateau above. The InSAR-measured displacement patterns, supplemented by field observations and optical satellite images, reveal complex slope activity; kinematically complex, steady-state creep along pre-existing sliding surfaces accelerated in response to heavy rainfall, after which slightly faster and expanded steady creeping was re-established. This case study demonstrates that high-quality ground-surface motion fields derived using spaceborne InSAR can help to characterize creep mechanisms, quantify spatial and temporal patterns of slope activity, and identify isolated small-scale instabilities; such details are especially useful where knowledge of landslide extent and activity is limited. Characterizing slope activity before, during, and after the 2011 Pampahasi landslide is particularly important for understanding landslide hazard in La Paz, half of which is underlain by similar large paleolandslides.</p>https://www.nat-hazards-earth-syst-sci.net/19/679/2019/nhess-19-679-2019.pdf |
| spellingShingle | N. J. Roberts B. T. Rabus J. J. Clague R. L. Hermanns R. L. Hermanns M.-A. Guzmán E. Minaya Changes in ground deformation prior to and following a large urban landslide in La Paz, Bolivia, revealed by advanced InSAR Natural Hazards and Earth System Sciences |
| title | Changes in ground deformation prior to and following a large urban landslide in La Paz, Bolivia, revealed by advanced InSAR |
| title_full | Changes in ground deformation prior to and following a large urban landslide in La Paz, Bolivia, revealed by advanced InSAR |
| title_fullStr | Changes in ground deformation prior to and following a large urban landslide in La Paz, Bolivia, revealed by advanced InSAR |
| title_full_unstemmed | Changes in ground deformation prior to and following a large urban landslide in La Paz, Bolivia, revealed by advanced InSAR |
| title_short | Changes in ground deformation prior to and following a large urban landslide in La Paz, Bolivia, revealed by advanced InSAR |
| title_sort | changes in ground deformation prior to and following a large urban landslide in la paz bolivia revealed by advanced insar |
| url | https://www.nat-hazards-earth-syst-sci.net/19/679/2019/nhess-19-679-2019.pdf |
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