CTBT: Science and Technology Conference 2023 - SnT2023

Continuous Analysis of International Monitoring System Hydrophone Array Signals for the Detection of Submarine Volcanic Activity

P1.3-566

20 Jun 2023, 09:00

1h

Wintergarten

Board: 10

E-poster T1.3 The Oceans and their Properties Lightning talks: P1.3, P1.4, P5.2

Speaker

Mr Satoru Tanaka (Japan Agency for Marine-Earth Science and Technology (JAMSTEC))

Description

International Monitoring System hydrophone stations are useful for the monitoring of submarine volcanic activity, especially in the western Pacific Ocean. Therefore, we started to routinely analyse the signals of triplet H11S, located off the coast of Wake Island, from July 2022 onwards. The SeedLink server of the Incorporated Research Institutions for Seismology (IRIS) provides the data; the SeisComP5 software is used for access and storage in daily mseed files. We process one-day hydrophone data as follows: 1. Removing the instrument response, 2. Band-pass filtering of the waveforms (4-8 Hz), 3. Semblance analysis to determine the incoming direction and apparent velocity across the triplet per 10-s time window, using intervals of 1° and 0.002 km/s (1.45 to 1.55 km/s), respectively, 4. The results are posted on our internal website. The obtained maximum semblance values typically vary from 0.5 to 0.9, and only values ≥ 0.7 are interpreted to be significant.

Promotional text

Processing of International Monitoring System hydrophone data (H11S) for signs of submarine volcanic activity.

Presentation materials

P1.3-566_Tanaka_lightning.pptx

P1.3-566_Tanaka.pptx