000019056 001__ 19056
000019056 005__ 20170118182257.0
000019056 04107 $$aeng
000019056 046__ $$k2017-01-09
000019056 100__ $$aGreen, Russell A.
000019056 24500 $$aOn the Distribution of Earthquake Strong-Motion Amplitudes and Site Effects Across the Icelandic Strong-Motion Arrays

000019056 24630 $$n16.$$pProceedings of the 16th World Conference on Earthquake Engineering
000019056 260__ $$b
000019056 506__ $$arestricted
000019056 520__ $$2eng$$aIn Iceland, the most seismically active region in northern Europe, large earthquakes occur almost exclusively in two major fracture zones, the South Iceland Seismic Zone (SISZ) in the populated and cultivated farmlands of south Iceland and the mostly offshore Tjörnes Fracture Zone (TFZ) in north Iceland. Both regions are known for being densely populated and have been historically subjected to destructive near-fault earthquake strong-motions. Generally speaking, populated urban areas in Iceland consist of structures of relatively similar construction. Although site effects are generally assumed to be negligible and regionally similar, recent data collected on new strong-motion arrays, the ICEARRAY-I in Hveragerði in the SISZ and ICEARRAY-II in Húsavík in the TFZ now provide the opportunity to investigate the geological impact on site responses and study spatial distribution of ground motions. In this study, we apply the Nakamura’s method using earthquake strong-motion data and microseismic measurements to assure the consistency of the results. To further investigations of geostructural influences on site responses, we present the spatial distribution maps for key parameters such as Peak Ground Acceleration (PGA) and Spectral Acceleration (SA) as a function of oscillator period as well as predominant frequency (f0) and the relative amplification (A0). Contrary to the fairly uniform site condition, the data exhibit variability across both arrays; however, despite the scatter of the results, we find a noticeable correlation between near surface geology and site response. Additionally, due to strong velocity reversals with depth due to repeated lava-sediment stratigraphy under most of ICEARRAY-I, we model it as a discrete dynamic structural system instead of using the body wave approximation. The results presented herein support the use of site effect investigations in combination with surface geology to improve seismic microzonation studies and also present a simple, practical and reliable strategy to model soil amplification in the presence of the velocity reversals.

000019056 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000019056 653__ $$aSite effect; HVSR; PGA; velocity reversal; array; Iceland.

000019056 7112_ $$a16th World Conference on Earthquake Engineering$$cSantiago (CL)$$d2017-01-09 / 2017-01-13$$gWCEE16
000019056 720__ $$aGreen, Russell A.$$iHalldórsson, Benedikt$$iRahpeyma, Sahar
000019056 8560_ $$ffischerc@itam.cas.cz
000019056 8564_ $$s1500527$$uhttps://invenio.itam.cas.cz/record/19056/files/2762.pdf$$yOriginal version of the author's contribution as presented on USB, paper 2762.
000019056 962__ $$r16048
000019056 980__ $$aPAPER