Seismic ground motion of sedimentary valleys - example La Molina, Lima, Peru
Article Sidebar
Main Article Content
Abstract
Strong motion accelerograms recorded at two sites in Lima, Peru, during the earthquake of November 9, 1974, exhibit serious dissimilarities although the sites have nearly the same epicentral distance. The two sites are the Instituto Geofisico del Peru in central Lima and the La Molina sediment-filled valley on the periphery of the city. The anomalously strong and prolonged ground motion at the La Molina site seems to be explained by a combined effect of the complex topography of the bedrock and the presence of low-velocity subsurface sediments. In contrast to an intuitive feeling, a strong velocity contrast along the whole sediment-bedrock interface is not necessary. Because severe earthquake effects in La Molina are of site origin, they should be expected to repeat in the future. As indicated by synthetic accelerograms, the anomaly refers to large areas of the La Molina valley and not only to the immediate vicinity of the recording point. For purposes of seismic microzoning and land-use planning, two microzones in the studied part of the valley will probably be appropriate.
ARK: https://n2t.net/ark:/88439/y042722
Permalink: https://geophysicsjournal.com/article/120
Article Details
Authors who publish with this journal as of Vol. 63 agree to the following terms:
a. Authors share the copyright with this journal in equal parts (50% to the journal, 50% to the lead author), and grant the journal right of first publication, with the work after publication simultaneously licensed under Creative Commons Attribution License CC BY-NC-ND 4.0 that allows others to share the work with an acknowledgment of the work's authorship and initial publication in this journal.
b. Authors may enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgment of its initial publication in this journal, and a reference to this copyright notice.
c. Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) during the submission process, as this can lead to productive exchanges and earlier and greater citation of published work and better sales of the copyright.
Author Self-archiving
Authors retain copyright and grant the Journal of Geophysics right of first publication, with the work three years after publication simultaneously licensed under the Creative Commons BY-NC-ND 4.0 License that allows others to share the work (with an acknowledgment of the work's authorship and initial publication in this journal), except for commercial purposes and for creating derivatives.
Authors can enter into separate, additional, but non-commercial contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository, but not publish it in a book), with an acknowledgment of its initial publication in this journal.
Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) before and during the submission process, as that can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).
Additional Notes
This journal is one of a handful of scholarly journals that publish original scientific works under CC BY-NC-ND 4.0 - the only Creative Commons license affording the authors' intellectual property absolute worldwide protection.
Journal of Geophysics is published under the scholar-publishers model, meaning authors do not surrender their copyright to us. Instead, and unlike corporate publishers like Elsevier or Springer Nature that resell copyright to third-parties for up to $80,000 (per paper, per transaction!), the Journal of Geophysics authors share copyright equally with this journal.
Therefore, all the proceeds from reselling copyright to third parties get shared to equal parts (50% to the journal, 50% to the lead author). Under the Berne Convention, this protection is an inheritable right that lasts for as long as the rightsholder lives + 50 years.
By submitting to this journal, the lead author, on behalf of all co-authors, grants permission to this journal to represent all co-authors in negotiating copyright sales and collecting proceeds. The lead author should negotiate with his/her co-authors the modalities of distributing the lead author's portion of the proceeds. Usually, this is per pre-agreed percentage of each co-author's contribution to creating the copyrighted work. (more...)
References
Brady, A.G., Perez, V. (1977) Strong-motion earthquake accelerograms, digitization and analysis; records from Lima, Peru: 1951 to 1974. Open-file report No. 77-587, U.S. Geological Survey, Menlo Park
Červeny, V. (1985) The application of ray tracing to the numerical modeling of seismic wavefields in complex structures. In: Dohr, G.P. (Ed.) Seismic shear waves, pp. 1-124. Geoph. Press, London
Deza, E., Berrocal, J., Silgado, E., Rodriguez, A., Carbonel, C. (1976) Intensidades observadas en Lima por el terremoto del 3 de Octubre de 1974 (informe). Instituto Geofisico del Peru, Lima
Emmerich, H., Korn, M. (1987) Incorporation of attenuation into timedomain computations of seismic wavefields. Geophysics 52 (In press)
Espinosa, A.F., Husid, R., Algermissen, S.T., De las Casas, J. (1977) The Lima earthquake of October 3, 1974: intensity distribution. Bull. Seismol. Soc. Am. 67, 1429-1439
Giesecke, A., Ocola, L., Silgado, E., Herrera, J., Giuliani, H. (1980) El terremoto de Lima del 3 de Octubre de 1974 (informe). Lima: CERESIS/UNESCO
Tucker, B.E., King, J.L. (1984) Dependence of sediment-filled valley response on input amplitude and valley properties. Bull. Seismol. Soc. Am. 74, 153-165
Zahradnik, J. (1982) Seismic response analysis of two-dimensional absorbing structures. Studia Geophys. at Geodaet. 26, 24-41
Zahradnik, J. (1985) Programs for computing and analysing SH wavefields in two-dimensional absorbing block structures. In: N.N. Matveeva (Ed.) Programs for interpreting seismic observations 3 (in Russian), pp. 124-186. Nauka, Leningrad
Zahradnik, J., Hron, F. (1986) Earthquake ground motion at the La Molina sedimentary basin, Lima, Peru. Res. Report to CERESIS, Lima (60 pp., 18 figs., available on request)
Zahradnik, J., Urban, L. (1984) Effect of a simple mountain range on underground seismic motion. Geophys. J.R. Astron. Soc. 79, 167-183