Scholarly record
INTENSITY-DISTANCE ATTENUATION FROM EMSC CROWDSOURCED MACROSEISMIC REPORTS IN ALBANIA, 2012-2026
Abstract
Crowdsourced macroseismic data provide an important complement to instrumental earthquake catalogues, especially where the spatial distribution of felt effects is influenced by population density, local site conditions and building vulnerability. This study presents a preliminary intensity-distance attenuation analysis based on EMSC crowdsourced macroseismic reports for Albania and nearby border areas during 2012-2026. The compiled database contains 694 earthquakes and 212,140 corrected macroseismic intensity points. After quality control, spatial filtering, intensity-range checks and exclusion of reports beyond 300 km hypocentral distance, the regression subset contains 663 earthquakes and 138,430 intensity points. Corrected macroseismic intensity was modelled as a function of magnitude and hypocentral distance using ordinary least squares regression. The preferred preliminary model is I = 1.249 + 0.905M - 1.288 log10(Rhypo). Model performance was evaluated using in-sample statistics, giving R2 = 0.175, RMSE = 1.348 and MAE = 1.005 intensity units. The residual scatter indicates that magnitude and distance explain the first-order attenuation trend, but not the full variability of crowdsourced felt reports. This variability is consistent with the influence of site effects, building type, floor level, population distribution, individual perception and reporting behaviour. The results show that EMSC felt reports can support a first-order regional attenuation relationship and the development of a WebGIS-based macroseismic database for Albania, while further calibration with EMS-98 field observations, ShakeMap products and historical macroseismic data remains necessary.
Publication details
References8
Grünthal, G. (Ed.), 1998. European Macroseismic Scale 1998 (EMS-98). Cahiers du Centre Européen de Géodynamique et de Séismologie, Vol. 15, Luxembourg, 99 pp.
Musson, R.M.W., Grünthal, G., Stucchi, M., 2010. The comparison of macroseismic intensity scales. Journal of Seismology, 14, 413-428.
Wald, D.J., Quitoriano, V., Worden, B., Hopper, M., Dewey, J.W., 2011. USGS 'Did You Feel It?' internet-based macroseismic intensity maps. Annals of Geophysics, 54(6), 688-707.
Quitoriano, V., Wald, D.J., 2020. USGS 'Did You Feel It?' - Science and lessons from twenty years of citizen science-based macroseismology. Frontiers in Earth Science, 8, 120.
Bakun, W.H., Wentworth, C.M., 1997. Estimating earthquake location and magnitude from seismic intensity data. Bulletin of the Seismological Society of America, 87(6), 1502-1521.
Bossu, R., Fallou, L., Landès, M., Roussel, F., Julien-Laferrière, S., Roch, J., Steed, R., 2020. Rapid public information and situational awareness after the November 26, 2019, Albania earthquake: lessons learned from the LastQuake system. Frontiers in Earth Science, 8, 235.
European-Mediterranean Seismological Centre, 2026. Earthquake information and crowdsourced felt reports / LastQuake system. EMSC, accessed 2026.
Bozo, Rr., Ormeni, Rr., Gjuzi, O., 2020. Evaluation of macroseismic field of 21 September 2019 Durres earthquake in Albania. J. Int. Environmental Application & Science, 15(3), 181-187