GIS-Based Mapping of Seismic Parameters for the Pyrenees

Abstract

In the present paper, three of the main seismic parameters, maximum magnitude -Mmax, b-value, and annual rate -AR, have been studied for the Pyrenees range in southwest Europe by a Geographic Information System (GIS). The main aim of this work is to calculate, represent continuously, and analyze some of the most crucial seismic indicators for this belt. To this end, an updated and homogenized Poissonian earthquake catalog has been generated, where the National Geographic Institute of Spain earthquake catalog has been considered as a starting point. Herein, the details about the catalog compilation, the magnitude homogenization, the declustering of the catalog, and the analysis of the completeness, are exposed. When the catalog has been produced, a GIS tool has been used to drive the parameters’ calculations and representations properly. Different grids (0.5 × 0.5° and 1 × 1°) have been created to depict a continuous map of these parameters. The b-value and AR have been obtained that take into account different pairs of magnitude–year of completeness. Mmax has been discretely obtained (by cells). The analysis of the results shows that the Central Pyrenees (mainly from Arudy to Bagnères de Bigorre) present the most pronounced seismicity in the range.

Analisis Seismisitas Dan Potensi Bahaya Bencana Seismik Pulau Sumatera Berdasarkan Data Gempa 1970-2020

“…Wilayah dengan 𝑏-value yang rendah (tinggi) adalah wilayah di mana batuan bawah permukaannya mengalami stres yang tinggi (rendah). Definisi lain 𝑏-value adalah rasio statistik gempa kecil relatif terhadap gempa besar (Kijko and Smit, 2012;Rigo et al, 2018;Amaro-Mellado and Bui, 2020). Dengan demikian, variasi spasial 𝑏-value dari satu wilayah ke wilayah yang lain bisa digunakan untuk melihat potensi bahaya gempa besar yang mungkin saja terjadi di wilayah tertentu pada masa yang akan datang (Singh, 2016;Rigo et al, 2018;Amaro-Mellado and Bui, 2020).…”

“…Definisi lain 𝑏-value adalah rasio statistik gempa kecil relatif terhadap gempa besar (Kijko and Smit, 2012;Rigo et al, 2018;Amaro-Mellado and Bui, 2020). Dengan demikian, variasi spasial 𝑏-value dari satu wilayah ke wilayah yang lain bisa digunakan untuk melihat potensi bahaya gempa besar yang mungkin saja terjadi di wilayah tertentu pada masa yang akan datang (Singh, 2016;Rigo et al, 2018;Amaro-Mellado and Bui, 2020). Oleh karena itu, akurasi tinggi hasil perhitungan 𝑀 c , 𝑏-value, dan 𝑎-value adalah penting yang hanya bisa dicapai jika jumlah data gempa yang digunakan adalah minimal 200 kejadian (Woessner and Wiemer, 2005).…”

“…Pendekatan maximum likelihood (Aki, 1965) adalah metode yang banyak digunakan untuk estimasi 𝑎-value dan 𝑏-value karena tidak memperhitungkan interdependensi variabel sehingga ketidakpastian hasil akhir perhitungan 𝑎 dan 𝑏 dapat direduksi (Nava et al, 2017;Amaro-Mellado and Bui, 2020). Dengan demikian, hasil perhitungan 𝑎 dan 𝑏 bisa diperoleh dengan akurasi tinggi.…”

“…Distribusi magnitudo pada ketiga plot gambar menunjukkan data statistik gempa pasca frekuensi tertinggi mengikuti penurunan eksponensial (Luen and Stark, 2012; ISSN: 2302-4216 © Prodi Fisika Jurusan Fisika 2022 Scholz, 2015;Amaro-Mellado et al, 2017). Penurunan eksponensial tersebut merupakan karakteristik statistik distribusi magnitudo yang memenuhi hukum Gutenberg-Richter (Nava et al, 2017;Rigo et al, 2018;Ray et al, 2019;Amaro-Mellado and Bui, 2020).…”

Geo-Informatics in Resource Management

“…The second group of manuscripts uses geographic information systems to support decision making. Maqbool et al [19] proposed a model for analysis of disaster management strategies at urban scales while Amaro and Tien [20] used Geographic Information System (GIS) to study seismic parameters to calculate and analyze seismic indicators. In addition, Wang et al [21] used base cartography, lithology and seismic intensity data and GIS modelling to quantitatively evaluate the ecological and geological environment bearing capacity along a mountain road to characterize those areas suitable and not suitable for construction as well as reserve development areas.…”