The Lurøy earthquake of August 31, 1819, with MS ~ 5.8 is, by many colleagues, rated as the largest in NW Europe in historical times (pre-1900) and even up to present. Local shaking manifestations were most spectacular with rock, stone and mud avalanches, mast-high waves in nearby Rana fjord and even liquefaction was reported. Most surprisingly, at epicentral distances exceeding 100 km except for Stockholm 800 km away, very few macroseismic observations are available. Another peculiarity was the lack of any significant housing damage even in the Lurøy parish itself. In a recent paper, we postulated that the earthquake was of moderate size, reestimated at MS ~ 5.1, but of shallow depth between 5 and 10 km causing the intense local shaking. In this article, we add a new dimension to the many Lurøy earthquake studies namely simulating the seismic wavefield response of Lurøy itself and adjacent areas characterized by steep topographic reliefs. We use a 3D finite difference scheme and compute ground motion in the 2–8 Hz band for a shear wave source with a focal depth of 5 km. Water covered areas are replaced by crystalline crust due to the sparsity of dense bathymetric data.
Main results are that the topography of the Lurøy, close to the mountain peak at 685 m, causes wavefield amplification by a factor of 20 and even stronger. Further away in the Rana fjord and surrounding areas, we also got strong amplification in particular where the relief is sharpest thus explaining triggering of avalanches in a quantitative manner. In other words, macroseismic observations would be biased upward due to the topographic focusing effects and unless properly corrected for may increase the final earthquake magnitude estimate. We take these results to strongly support our claim that the historic Lurøy earthquake was of moderate size of MS ~ 5.1 and not at MS ~ 6.0 class as claimed by many colleagues. The largest magnitude estimates stem from including outlier observations in Kola and Stockholm. Finally, downscaling of maximum earthquake magnitude would also lower the seismic risk levels significantly.
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References
Ambraseys, N. N., 1985. The seismicity of Western Scandinavia. Earthq. Eng. Struct. Dyn. 13, 361–399.
Bannister, S. C., Husebye, E. S., Ruud, B. O., 1990. Teleseismic P-coda analyzed by three component and array technique–deterministic location of topographic P-to-Rg scattering near the NORESS array. Bull. Seism. Soc. Am. 80, 1969–1986.
Bungum, H, Hokland, B. K., Husebye, E. S. Ringdal, F., 1979. An exceptional intraplate earthquake sequence in Meløy, Northern Norway. Nature, 280, 5717, 32–35.
Bungum, H., Olesen O., 2005. The 31st of August 1819 Lurøy Earthquake revisited. Norwegian J. Geology, 85, 245–252.
Cerjan, C., Kosloff, D., Kosloff, R. and Reshef, M., 1985. Short note on a non-reflecting boundary condition for discrete acoustic-wave and elastic-wave equations. Geophysics, 50, 705–708.
Geli, L., Bard, P. Y., Jullien, B., 1988. The effect of topography on earthquake ground motion: a review and new results. Bull. Seism. Soc. Am. 78, 42–63.
Grunthal, G., Wahlstrøm, R., 2003. A Mw based earthquake catalogue for central, northern and northwestern Europe using a hierarchy of magnitude conversions. J. of Seismology, 7, 507–531.
Heltzen, I. A., 1834. Ranens beskrivelse. Rana Museum og Historielag. Mo i Rana, 290.
Hestholm, S. O., Husebye, E. S., Ruud, B. O., 1994. Seismic wave propagation in complex crust–upper mantle media using 2D finite difference synthetics. Geophys. J. Int. 118, 643–670.
Hestholm, S. O., Ruud, B. O., 1998. 3-D finite difference elastic wave modeling including surface topography. Geophysics, 63, 613–622.
Hestholm, S., Moran, M., Ketcham, S., Anderson, T., Dillen, M., McMechan, G., 2006. Effects of free-surface topography on moving-seismic-source modeling. Geophysics, 71, T159–T166.
Hestholm, S. O., Ruud, B. O., 2002. 3D free-boundary conditions for coodinate-transform finite-difference seismic modeling. Geophys. Prosp. 50, 463–474.
Hicks, E.C., 1996. Crustal stresses in Norway and surrounding areas as derived from earthquake focal mechanism solutions and in-situ stress measurements. M.Sc. Thesis, Dept. of Geology, UoOslo, Oslo, Norway, 164 pp.
Hicks, E. C., Bungum, Lindholm, C. D., 2000. Seismic activity, inferred crustal stresses and seismotectonics in the Rana region, northern Norway. Quaternary Science Reviews, 19, 1423–1436.
Husebye, E. S., 2005. Comments on the Lurøy earthquake controversy. Norwegian J. Geology 85, 253–256.
Husebye, E. S., Kebeasy, T. R. M., 2004. A re-assessment of the 31st of August 1819 Lurøy earthquake–Not the largest in NW Europe. Norwegian J. Geol. 84, 57–66.
Husebye, E. S., Kebeasy, T. R. M., 2005. Historical earthquakes in Fennoscandia–how large?. Physics Earth Planetary Interior 149, 355–359.
Husebye, E. S., Mäntyniemi, P., 2005. The Kaliningrad, West Russia earthquake on the 21st of September–surprise events In a very low-seismicity area. Physics Earth Planetary Interiors, 153, 227–236.
Kebeasy, T. R. M., Husebye, E. S., 2003a. A finite-difference approach for simulating ground responses in sedimentary basins: qualitative modeling of the Nile Valley, Egypt. Geophy. J. Int. 154, 913–924.
Kebeasy, T. R. M., Husebye, E. S., 2003b. Revising the 1759 Kattegat earthquake questionnaires using synthetic wave field analysis. Physics of Earth & Planetary Interiors, 139, 269–284.
Keilhau, B. M., 1836. Efterretninger om jordkjælv i Norge. Magasin for Naturvidenskaperne, 12, 83–165.
Kijko, A., 2008. Data driven probabilistic seismic hazard assement procedure for regions with uncertain seismogenic zones. In E.S. Husebye (ed.) Earthquake Monitoring and Seismic Hazard in Balkan Countries. Springer Publishing, Berlin, 237–251. ibid.
Kjellen, R., 1910. Sveriges jordskalf. Forsøk til en svensk landsgeografi. Gøteborgs Høgskolas Årsskrift, 15, 1–211.
Kinck, J. J., Husebye, E. S., Larsson, F. R., 1993. The moho depth distribution in Fennoscandia and the regional tectonic evolution from Archean to Permian times. Precambrian Res. 64, 23–51.
Kliche, C. A., 1999. Rock slope stability. Socity for Mining, Metallurgy, and Exploration (SME), Inc., Littleton, CO.
Kolderup, C. F., 1913. Norges jordskjKlv med slrlig hensyn til deres utbredelse i rum og tid. Bergen Museum Aarbok, 8, 152.
Kramer, S. L., 1996. Geotechnical earthquake engineering Prentice-Hall, New York 653 pp.
Mäntyniemi, P., Husebye, E. S, Kebeasy, T. R. M., Nikonov, A. A., Nikulin, V., Pacesa, A., 2004. State-of-the-art of historical earthquake research in Fennoscandia and the Baltic Republics. Annali Di Geofisica, 47, 611–619.
Moczo, P., Rovelli, A., Labak, P., Malagnini, L., 1995. Seismic response of the geological structure underlying Roman Colosseum. Annali di Geofisica 38, 939–956.
Moczo, P., Lucka, M., Kristek, J., Kristekova, M., 1999. 3D displacement dinite differences and a combined memory optimization. Bull. Seismol. Soc. Am. 89, 69–79.
Mokrov, E., Chernouss, P., Fedorenko, Yu. V., Husebye, E. S., 2000. The influence of seismic effects on avalanche release. In Proceed. Int. Snow Sci. Workshop ISSW-2000, Big Sky, MT, 338–341.
Muir Wood, R., 1989. The Scandinavian earthquakes of 22 December 1759 and 31 August 1819, Disasters, 12, 223–236.
Olesen. O., Dehls, J., Olsen, L., Blikra, L. H., Rise, L., Bungum, H., Lindholm, C. D., Hicks, E., Riis, F., Bockmann, L., 1999. Mor Norge rører på seg, GEO 2, 12–17.
Olsen, K. B., Nigbor, R., Konno, T., 2000. 3D viscoelastic wave propagation in the upper Borrego Valley, California, constrained by Borehole and surface data. Bull. Seis. Soc. Am. 90, 134–150.
Pitarka, A., 1999. 3D elastic finite difference modeling of seismic wave propagation using staggered-grid non-uniform spacing. Bull. Seism. Soc. Am. 89, 54–68.
Selby, M. J., 1980. A rock mass strength classification for geomorphic purposes: with tests from Antarctica and New Zealand. Zeitschrift fur Geomorphologie, 24, 31–51.
Stewart, I. S., Sauber, J., Rose, J., 2000. Glacio-seismotectonics: ice sheets, crustal deformation and seismicity. Quarterly Sci. Rev. 19, 1367–1389.
Wahlstrøm, R., 2004. Two large historical earthquakes in Fennoscandia still large. Phys. Earth Planet. Inter. 145, 253–258.
Wu, P., Johnston, P., Lambeck, K., 1999. Postglacial rebound and fault instability in Fennoscandia. Geophys. J. Int. 139, 657–670.
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Kebeasy, T.R.M., Husebye, E.S., Hestholm, S. (2008). Are Rock Avalanches and Landslides Due to Large Earthquakes or Local Topographic Effects? A Case Study of the Lurøy Earthquake of August 31, 1819, A 3D Finite Difference Approach. In: Husebye, E.S. (eds) Earthquake Monitoring and Seismic Hazard Mitigation in Balkan Countries. NATO Science Series: IV: Earth and Environmental Sciences, vol 81. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-6815-7_18
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