KRDAE SİSMİK AĞI GENİŞBAND GÜRÜLTÜ ANALİZİ

Öz

Gelişen teknolojiyle birlikte dünya genelinde deprem istasyonu ve sismik ağ sayısı hızla artmıştır. Türkiye’de Boğaziçi Üniversitesi Kandilli Rasathanesi ve Deprem Araştırma Enstitüsü (KRDAE), 1976’dan bu yana Türkiye Deprem Ağı’nı işletmektedir. Başlangıçta istasyonlar yerleşim yerlerinden uzak, gürültüsüz ve sağlam zeminli alanlara kurulmuş olsa da, zamanla artan kentleşme ve elektronik donanım değişiklikleri nedeniyle arka plan sismik gürültüsü (ASG) artmıştır. Bu durum, kaydedilebilecek minimum deprem büyüklüğünün yükselmesine neden olmaktadır. Bu çalışmada, KRDAE-BDTİM’e ait mevcut istasyonların gürültü analizleri yapılmış, en gürültülü istasyonlarda elektronik kaynaklı sinyaller belirlenerek iyileştirme çalışmaları gerçekleştirilmiştir. Gürültü giderilemeyen istasyonlar için yeni yer seçimleri önerilmiştir. Pilot bölge olarak istasyon yoğunluğu ve mikrodeprem potansiyeli nedeniyle Marmara Bölgesi seçilmiştir. Gürültülü üç istasyonda arazi çalışmaları yapılarak iyileştirme sonrası veriler analiz edilmiştir. Ayrıca, PQLX yazılımına alternatif MATLAB tabanlı yerli bir yazılım geliştirilmiş ve karşılaştırmalı analiz yapılmıştır. 2024 yılı için BDTİM’de kullanılan mevcut geniş bant istasyonlarının sinyal güç içeriği Python tabanlı programlar kullanılarak hesaplanmış, normalleştirilmiş güç spektral yoğunluğu (PSD) verileri KRDAE-BDTİM web sayfasında paylaşılmıştır.

Anahtar Kelimeler

• Arka plan sismik gürültü
• Sismik istasyon
• Marmara Bölgesi
• Yer seçimi

KRDAE SEISMIC NOISE ANALYSIS

Öz

This study presents a comprehensive seismic noise analysis of broadband stations operated by the Boğaziçi University Kandilli Observatory and Earthquake Research Institute (KRDAE), which has managed the national seismic network in Türkiye since 1976. Over time, increasing urbanization and upgrades in electronic instrumentation have led to a rise in background seismic noise (BSN), which limits the detection of small-magnitude events and affects overall data quality. The primary objective is to identifying and mitigating noise sources, particularly those of electronic origin, at selected stations. Alternative site locations were proposed for stations where noise mitigation was not fesaible. The Marmara Region was chosen as a pilot area due to its dense station coverage and the potential to record microseismicity. Field investigations were conducted at three noisy stations, and data collected after on-site improvements were compared with initial records. A MATLAB-based domestic software tool was developed as an alternative to the widely used PQLX software, and a comparative evaluation was performed. Additionally, during 2024, seismic data from current broadband stations were processed using Python-based programs to compute and normalize the Power Spectral Density (PSD), and the results were published on the KRDAE-BDTİM website for open access by the research community.

Anahtar Kelimeler

• Ambient seismic noise
• Seismic station
• Marmara Region
• Site selection

Kaynakça

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