日本地球惑星科学連合2019年大会

講演情報

[J] ポスター発表

セッション記号 S (固体地球科学) » S-VC 火山学

[S-VC38] 活動的火山

2019年5月27日(月) 10:45 〜 12:15 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:前田 裕太(名古屋大学)、三輪 学央(防災科学技術研究所)、西村 太志(東北大学大学院理学研究科地球物理学専攻)

[SVC38-P11] Real time monitoring of underground temperature in Jigokudani, Midagahara volcano using LPWA devices

*渡辺 了1西日本電信電話株式会社 富山支店2 (1.富山大学大学院理工学研究部、2.西日本電信電話株式会社)

キーワード:地中温度、LPWA、リアルタイム観測

Jigokudani is an active geothermal area in Midagahara volcano, Toyama prefecture, central Japan. It was formed as a result of repeated phreatic eruptions over 40,000 years. Increased volcanic activity in this area has been observed since 2011. In order to detect a precursory signal of a phreatic eruption, seismicity, observations should be conducted on seismicity, ground deformation, geothermal activity, volcanic gas, etc. A real time monitoring system of underground temperature using LPWA (Low Power, Wide Area) devices has been tested since 30 August 2018. An LPWA device (NHR, SS05-ST) is composed of thermometer and transmitter (LoRaWAN). 10 devices were deployed in Jigokudani. Temperature sensors (thermocouples) were placed at the depth of 50 cm. Transmitters send temperature data every 30 minutes to a gateway to the internet situated in Hotel Tateyama. The distances from the gateway to LPWA devices are within 1 km. Underground temperatures can be monitored on internet devices. Since Jigokudani has a heavy snowfall in winter, 7 devices were removed and 3 devices were left to test in winter. Though temperature data could be received until December 2018, no data could be received since then. Transmitters of around 50 cm high above the ground must be covered with snow. During summer and fall, LPWA devices are useful for real time monitoring.