scholarly journals Aftershock observation of the Noto Hanto earthquake in 2007 using ocean bottom seismometers

2008 ◽  
Vol 60 (10) ◽  
pp. 1005-1010 ◽  
Author(s):  
Tomoaki Yamada ◽  
Kimihiro Mochizuki ◽  
Masanao Shinohara ◽  
Toshihiko Kanazawa ◽  
Asako Kuwano ◽  
...  
2008 ◽  
Vol 59 ◽  
pp. 65-82 ◽  
Author(s):  
Akira Yamazaki ◽  
Shigeki Aoki ◽  
Yasuhiro Yoshida ◽  
Akio Kobayashi ◽  
Akio Katsumata ◽  
...  

2005 ◽  
Vol 57 (4) ◽  
pp. 363-368 ◽  
Author(s):  
Shin’ichi Sakai ◽  
Tomoaki Yamada ◽  
Masanao Shinohara ◽  
Hiroko Hagiwara ◽  
Toshihiko Kanazawa ◽  
...  

2001 ◽  
Vol 106 (B12) ◽  
pp. 30689-30699 ◽  
Author(s):  
Kei Katsumata ◽  
Toshinori Sato ◽  
Junzo Kasahara ◽  
Naoshi Hirata ◽  
Ryota Hino ◽  
...  

1981 ◽  
Vol 71 (5) ◽  
pp. 1649-1659
Author(s):  
Thomas M. Brocher ◽  
Brian T. Iwatake ◽  
Joseph F. Gettrust ◽  
George H. Sutton ◽  
L. Neil Frazer

abstract The pressures and particle velocities of sediment-borne signals were recorded over a 9-day period by an array of telemetered ocean-bottom seismometers positioned on the continental margin off Nova Scotia. The telemetered ocean-bottom seismometer packages, which appear to have been very well coupled to the sediments, contained three orthogonal geophones and a hydrophone. The bandwidth of all sensors was 1 to 30 Hz. Analysis of the refraction data shows that the vertical geophones have the best S/N ratio for the sediment-borne signals at all recording depths (67, 140, and 1301 m) and nearly all ranges. The S/N ratio increases with increasing sensor depth for equivalent weather conditions. Stoneley and Love waves detected on the Scotian shelf (67-m depth) are efficient modes for the propagation of noise.


2010 ◽  
Vol 10 (8) ◽  
pp. 1759-1780
Author(s):  
O. Boebel ◽  
M. Busack ◽  
E. R. Flueh ◽  
V. Gouretski ◽  
H. Rohr ◽  
...  

Abstract. The German-Indonesian Tsunami Early Warning System (GITEWS) aims at reducing the risks posed by events such as the 26 December 2004 Indian Ocean tsunami. To minimize the lead time for tsunami alerts, to avoid false alarms, and to accurately predict tsunami wave heights, real-time observations of ocean bottom pressure from the deep ocean are required. As part of the GITEWS infrastructure, the parallel development of two ocean bottom sensor packages, PACT (Pressure based Acoustically Coupled Tsunameter) and OBU (Ocean Bottom Unit), was initiated. The sensor package requirements included bidirectional acoustic links between the bottom sensor packages and the hosting surface buoys, which are moored nearby. Furthermore, compatibility between these sensor systems and the overall GITEWS data-flow structure and command hierarchy was mandatory. While PACT aims at providing highly reliable, long term bottom pressure data only, OBU is based on ocean bottom seismometers to concurrently record sea-floor motion, necessitating highest data rates. This paper presents the technical design of PACT, OBU and the HydroAcoustic Modem (HAM.node) which is used by both systems, along with first results from instrument deployments off Indonesia.


2020 ◽  
Vol 91 (2A) ◽  
pp. 803-813 ◽  
Author(s):  
Telluri Ramakrushana Reddy ◽  
Pawan Dewangan ◽  
Lalit Arya ◽  
Pabitra Singha ◽  
Kattoju Achuta Kamesh Raju

Abstract We observed a harmonic noise (HN) in DEutscher Geräte-Pool für Amphibische Seismologie ocean-bottom seismometers (OBSs) data recorded from the Andaman–Nicobar region. The HN is characterized by sharp spectral peaks with a fundamental frequency and several overtones occurring at integer multiples of the fundamental frequency. We used an automated algorithm to quantify the occurrence of HN for the entire four-month deployment period (1 January 2014 to 30 April 2014). The algorithm detected more than 23 days of HN for some OBS stations. The spectral analysis of the hourly count of HN shows distinct lunar and solar tidal periodicities at 4.14, 6.1, 6.22, 12, and 12.4 hr as well as 13.66 days. The observed periodicities provide evidence of tidal triggering of HN. The HN is generated by the strumming of head buoys due to seafloor currents initiated by oceanic tides in the Andaman–Nicobar region.


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