Seismic test data and resolution analysis from the first borehole broadband seismometers at Mt. Etna, Sicily (Italy), as part of the SiC nano for PicoGeo project

In October 2021, GFZ installed together with INGV Catania, Iraci and ASIR Ltd (Advances Seismic Instrumentation & Research) the very first seismic borehole broadband seismometers at two selected sites at Mt. Etna, Sicily (see Fig. 1). The installation was completed under the EU-funded project ‘SiC nano for PicoGeo’ (http://www.picogeo.eu/). Site one is located next to the Astrophysical Observatory at Serra La Nave (SLN) and site two is located in the city of Mascalucia (MAS). At each site one borehole broadband seismometer was permanently installed (cemented) at approximately 70 m depth. In approx. 1-2m distance, a second ground-level borehole 4.5 Hz Geophone was temporarily installed (sanded) at 1 m depth until July 2022 (see Fig. 2). The ground-level geophones served as a local surface reference sensor to better evaluate the increase of signal quality from surface to depth. Test data were evaluated between October 2021 and July 2022. Sensor settings were adjusted during this time period to obtain the best possible data resolution at both test sites. This data publication compiles a segment of waveform recordings utilized for the assessment of data quality from the two installed broadband borehole seismometers, along with noise plots (Fig. 3-5) illustrating the enhancements in the data quality of frequency ranges compared to surface sensors at Mt. Etna.

2021年10月，德国波茨坦地球科学研究中心（GFZ）与意大利国家地球物理与火山学研究所卡塔尼亚分部（INGV Catania）、Iraci及ASIR有限公司（Advances Seismic Instrumentation & Research）合作，在西西里岛埃特纳火山的两处选定场址安装了首批钻孔式宽带地震仪，详见图1。本次部署由欧盟资助的“SiC nano for PicoGeo”项目（http://www.picogeo.eu/）支持完成。场址1设于塞拉拉纳夫（Serra La Nave，SLN）天体物理天文台附近，场址2位于马斯卡卢西亚（Mascalucia，MAS）市内。每处场址均在约70米深度处永久安装了一台钻孔式宽带地震仪（采用水泥固定）；在距离该仪器约1-2米处，于2022年7月前临时在1米深度处安装了一台地表式4.5Hz检波器（采用砂土固定），详见图2。该地表检波器作为本地地表参考传感器，用于更精准地评估从地表到深部的信号质量提升情况。测试数据的评估周期为2021年10月至2022年7月，在此期间研究人员对传感器参数进行了调整，以在两处测试场址获得最优的数据分辨率。本数据集收录了用于评估两台安装的钻孔式宽带地震仪数据质量的一段波形记录，以及图3至图5所示的噪声图谱，用以展示埃特纳火山地区深部传感器相较于地表传感器在各频段的信号质量提升效果。