Innovation of observational method in deep seafloor for high density seismological observation

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K21909
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 17:Earth and planetary science and related fields
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: Araki Eiichiro 国立研究開発法人海洋研究開発機構, 海域地震火山部門(地震津波予測研究開発センター), グループリーダー (60359130)
• Project Period (FY): 2019-06-28 – 2024-03-31
• Keywords: 超小型海底地震計 / 稠密観測 / ローコスト

Outline of Final Research Achievements

We developed an ultra-compact and low-cost seafloor seismic observation instrument that can plan array observations with unprecedented density and quantity on the deep sea floor. The configuration consists of a lithium-ion rechargeable batteries, three-component geophones, a gimbal for horizontal leveling, observation processing board, and optical communication board for visible light communication, all mounted in a 13-inch 4000m pressure-resistant glass sphere, and capable of synchronizing time, starting and stopping observations via visible light communication.
The developed observation processing board for the ultra-compact ocean bottom seismometer was used to make a seafloor pressure observation system, and long-term continuous pressure measurements were conducted off Izu Oshima Island from July 2021, and the data was recovered by a ROV to confirm the long-term reliability of the observation processing system.

Free Research Field

Seismology

Academic Significance and Societal Importance of the Research Achievements

本研究の技術開発によって、沈み込む海域プレート境界部で発生するスロー地震のメカニズムを探求するために必要な稠密かつ長期のアレイ海底地震観測を計画するために必要な基礎技術が進化した。また本研究での、ローコストな観測装置の開発と長期観測による検証を通じて、海底地震以外の海底水圧観測などについても、これまでにない観測が実現された。