Improving data, metadata and service quality within Résif-SI

<p>Résif, the French seismological and geodetic network, was launched in 2009 in an effort to develop, modernize, and centralize geophysical observation of the Earth’s interior. This French research infrastructure uses both permanent and mobile instrument networks for continuous seismological, geodetic and gravimetric measurements.</p><p>Résif-SI is the Information System that manages, validates and distributes seismological data from Résif.</p><p>The construction of Résif-SI has lead to a federated organisation gathering several data and metadata producers (Nodes) and a national Seismological Data Centre.</p><p>The Résif Seismological Data Centre is one of 19 global centres distributing data and metadata in formats and using protocols which comply with International Federation of Digital Seismograph Networks (FDSN) standards. It is also one of the eleven nodes in EIDA, the European virtual data centre and seismic data portal in the European Plate Observing System (EPOS) framework.</p><p>Inside Résif-SI, each Node has it's specificities and dedicated procedures in order to manage and validate the data and metadata workflow from the station instruments to the Résif Seismological Data Centre.</p><p>To meet the expectations and needs of the end user in terms of data quality, metadata consistency and service availability, Résif-SI operates a complex set of quality enhancement operations.</p><p>This contribution will present the quality expectations that are in the core of Résif-SI, and show the methods and tools that help us meeting the expectations, and that could be of interest for the rest of the community.</p><p>We will then list some of our quality improvement projets and the expected results.</p>

Shallow Magmatic Hydrothermal Eruption in April 2018 on Ebinokogen Ioyama Volcano in Kirishima Volcano Group, Kyushu, Japan

The Kirishima Volcano Group is a volcanic field ideal for studying the mechanism of steam-driven eruptions because many eruptions of this type occurred in the historical era and geophysical observation networks have been installed in this volcano. We made regular geothermal observations to understand the hydrothermal activity in Ebinokogen Ioyama Volcano. Geothermal activity resumed around the Ioyama from December 2015. A steam blowout occurred in April 2017, and a hydrothermal eruption occurred in April 2018. Geothermal activity had gradually increased before these events, suggesting intrusion of the magmatic component fluids in the hydrothermal system under the volcano. The April 2018 eruption was a magmatic hydrothermal eruption caused by the injection of magmatic fluids into a very-shallow hydrothermal system as a bottom–up fluid pressurization, although juvenile materials were not identifiable. Additionally, the upwelling of mixed magma–meteoric fluids to the surface as a kick was observed just before the eruption to cause the top–down flashing of April 2018. A series of events was generated in the shallower hydrothermal regime consisting of multiple systems divided by conductive caprock layers.

ESTIMATION OF LONG-RANGE CORRELATION SCALES BY SEISMOACOUSTIC EMISSION SIGNALS OF NEAR-SURFACE SEDIMENTARY ROCKS IN KAMCHATKA

На Камчатке в пункте комплексных геофизических наблюдений ИКИР ДВО РАН Карымшина для регистрации сигналов сейсмоакустической эмиссии на поверхности земли установлен измерительный комплекс. В качестве датчика сигналов используется трехкомпонентный пьезокерамический сейсмоприемник, который регистрирует колебательное ускорение в частотном диапазоне 0.5-400 Гц. Рассмотрен сейсмоакустический отклик на несколько региональных землетрясений с энергетическим классом Ks 11:0 в период 2017-2018 гг. При помощи статистических методов установлено самоподобие их структуры на ограниченном интервале временных масштабов. Это, в свою очередь, указывает на наличие дальних корреляций в рассматриваемой системе и позволяет получить оценку масштабов корреляций. A measurement complex is installed on the ground surface at Karymshina complex geophysical observation site of IKIR FEB RAS (Kamchatka) to record seismoacoustic emission signals. A three-component piezoceramic seismic receiver, which records oscillatory acceleration in the frequency range from 0.2 to 400 Hz, is used as the signal sensor. A series of seismoacoustic responses on regional earthquakes of 2017-2018 with the energy class Ks 11:0 has been considered. Self-similarity of their structures has been established in a limited interval of time scales by statistical methods. That, in its turn, indicates the presence of long-range correlations in the system under consideration and allows one to estimate correlation scales.

Seismic Vulnerability Maps of Ratu Agung District, Bengkulu City, Indonesia

During the 8.6 Mw Bengkulu-Mentawai Earthquake Ratu Agung District was identified as an impacted area. This paper aims to deliver the seismic vulnerability based on geophysical observation. This study was initiated by performing the ambient noise measurement to obtain the geophysical characteristic, such as amplification and predominant frequency. Furthermore, the vulnerability index analysis was performed from the geophysical information collected from the investigation. To observe the tendency of ground damage during the earthquake, ground damages analysis is also performed. All results are depicted into the microzonation maps. The results showed that the amplification and predominant frequency on site are generally ranging from 3 to 5 and 5 to 8 Hz, respectively. The seismic vulnerability index in study area is up to 10-3. The results showed that during the Bengkulu-Mentawai Earthquake, the investigated sites could be possible to undergo crack settlement which can trigger massive sand boiling in the study area.