scholarly journals Crustal structure of the Kolbeinsey Ridge, North Atlantic, obtained by use of ocean bottom seismographs

1997 ◽  
Vol 102 (B2) ◽  
pp. 3131-3151 ◽  
Author(s):  
Shuichi Kodaira ◽  
Rolf Mjelde ◽  
Karl Gunnarsson ◽  
Hajime Shiobara ◽  
Hideki Shimamura
Keyword(s):  
Crustal Structure ◽  
North Atlantic ◽  
Ocean Bottom ◽  
Ocean Bottom Seismographs

Crustal structure of the central part of the Vøring Basin, mid-Norway margin, from ocean bottom seismographs

1997 ◽  
Vol 277 (4) ◽  
pp. 235-257 ◽  
Author(s):  
R. Mjelde ◽  
S. Kodaira ◽  
H. Shimamura ◽  
T. Kanazawa ◽  
H. Shiobara ◽  
...  
Keyword(s):  
Crustal Structure ◽  
Ocean Bottom ◽  
Ocean Bottom Seismographs ◽  
Vøring Basin

Crustal Structure in the Vøring Basin, Northern Norway, from Three-Component Ocean Bottom Seismographs

1995 ◽  
Author(s):  
R. Mjelde ◽  
S. Kodaira ◽  
H. Shimamura ◽  
H. Shiobara ◽  
T. Kanazawa ◽  
...  
Keyword(s):  
Crustal Structure ◽  
Ocean Bottom ◽  
Northern Norway ◽  
Ocean Bottom Seismographs ◽  
Vøring Basin

scholarly journals Crustal Structure of the Yamato Basin and the Margin of the Northeastern Japan Sea Using Ocean Bottom Seismographs and Controlled Sources

2001 ◽  
Vol 54 (3) ◽  
pp. 365-379 ◽  
Author(s):  
Hiromasa NISHISAKA ◽  
Masanao SHINOHARA ◽  
Toshinori SATO ◽  
Ryota HINO ◽  
Kimihiro MOCHIZUKI ◽  
...  
Keyword(s):  
Crustal Structure ◽  
Japan Sea ◽  
Ocean Bottom ◽  
Northeastern Japan ◽  
Yamato Basin ◽  
Ocean Bottom Seismographs

Queen Charlotte fault zone: microearthquakes from a temporary array of land stations and ocean bottom seismographs

1981 ◽  
Vol 18 (4) ◽  
pp. 776-788 ◽  
Author(s):  
R. D. Hyndman ◽  
R. M. Ellis
Keyword(s):  
Fault Zone ◽  
Strike Slip ◽  
Ocean Bottom ◽  
Small Component ◽  
Queen Charlotte Islands ◽  
The North ◽  
Vertical Fault ◽  
Linear Sections ◽  
Ocean Bottom Seismographs ◽  
Steep Slopes

A temporary array of land and ocean bottom seismograph stations was used to accurately locate microearthquakes on the Queen Charlotte fault zone, which occurs along the continental margin of western Canada. The continental slope has two steep linear sections separated by a 25 km wide irregular terrace at a depth of 2 km. Eleven events were located with magnitudes from 0.5 to 2.0, 10 of them beneath the landward one of the two steep slopes, some 5 km off the coast of the southern Queen Charlotte Islands. No events were located beneath the seaward and deeper steep slope. The depths of seven of these events were constrained by the data to between 9 and 21 km with most near 20 km. The earthquake and other geophysical data are consistent with a near vertical fault zone having mainly strike-slip motion. A model including a small component of underthrusting in addition to strike-slip faulting is suggested to account for the some 15° difference between the relative motion of the North America and Pacific plates from plate tectonic models and the strike of the margin. One event was located about 50 km inland of the main active zone and probably occurred on the Sandspit fault. The rate of seismicity on the Queen Charlotte fault zone during the period of the survey was similar to that predicted by the recurrence relation for the region from the long-term earthquake record.

scholarly journals Ocean-Bottom Seismographs Based on Broadband MET Sensors: Architecture and Deployment Case Study in the Arctic

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3979
Author(s):  
Artem A. Krylov ◽  
Ivan V. Egorov ◽  
Sergey A. Kovachev ◽  
Dmitry A. Ilinskiy ◽  
Oleg Yu. Ganzha ◽  
...  
Keyword(s):  
Site Response ◽  
The Arctic ◽  
Laptev Sea ◽  
Ocean Bottom ◽  
Arctic Seas ◽  
Shirshov Institute ◽  
Study Results ◽  
Ocean Bottom Seismographs ◽  
The Laptev Sea

The Arctic seas are now of particular interest due to their prospects in terms of hydrocarbon extraction, development of marine transport routes, etc. Thus, various geohazards, including those related to seismicity, require detailed studies, especially by instrumental methods. This paper is devoted to the ocean-bottom seismographs (OBS) based on broadband molecular–electronic transfer (MET) sensors and a deployment case study in the Laptev Sea. The purpose of the study is to introduce the architecture of several modifications of OBS and to demonstrate their applicability in solving different tasks in the framework of seismic hazard assessment for the Arctic seas. To do this, we used the first results of several pilot deployments of the OBS developed by Shirshov Institute of Oceanology of the Russian Academy of Sciences (IO RAS) and IP Ilyinskiy A.D. in the Laptev Sea that took place in 2018–2020. We highlighted various seismological applications of OBS based on broadband MET sensors CME-4311 (60 s) and CME-4111 (120 s), including the analysis of ambient seismic noise, registering the signals of large remote earthquakes and weak local microearthquakes, and the instrumental approach of the site response assessment. The main characteristics of the broadband MET sensors and OBS architectures turned out to be suitable for obtaining high-quality OBS records under the Arctic conditions to solve seismological problems. In addition, the obtained case study results showed the prospects in a broader context, such as the possible influence of the seismotectonic factor on the bottom-up thawing of subsea permafrost and massive methane release, probably from decaying hydrates and deep geological sources. The described OBS will be actively used in further Arctic expeditions.

Turbidity Current in the Northern Suruga Bay Recorded by Ocean Bottom Seismographs after Passing Typhoon No. 24 in 2018

2021 ◽  
Vol 73 (0) ◽  
pp. 197-207
Author(s):  
Hisatoshi BABA ◽  
Nagisa NAKAO ◽  
Takahito NISHIMIYA ◽  
Masanao SHINOHARA ◽  
Shintaro ABE ◽  
...  
Keyword(s):  
Turbidity Current ◽  
Ocean Bottom ◽  
Suruga Bay ◽  
Ocean Bottom Seismographs

Characteristics of Low-Frequency Horizontal Noise of Ocean-Bottom Seismic Data

2021 ◽  
Author(s):  
Chao An ◽  
Chen Cai ◽  
Lei Zhou ◽  
Ting Yang
Keyword(s):  
Water Waves ◽  
Noise Source ◽  
Random Noise ◽  
Low Frequency ◽  
Ocean Bottom ◽  
Coherent Noise ◽  
Infragravity Waves ◽  
Low Frequencies ◽  
Bottom Currents ◽  
Ocean Bottom Seismographs

Abstract Horizontal records of ocean-bottom seismographs are usually noisy at low frequencies (< 0.1 Hz). The noise source is believed to be associated with ocean-bottom currents that may tilt the instrument. Currently horizontal records are mainly used to remove the coherent noise in vertical records, and there has been little literature that quantitatively discusses the mechanism and characteristics of low-frequency horizontal noise. In this article, we analyze in situ ocean-bottom measurements by rotating the data horizontally and evaluating the coherency between different channels. Results suggest that the horizontal noise consists of two components, random noise and principle noise whose direction barely changes in time. The amplitude and the direction of the latter are possibly related to the intensity and direction of ocean-bottom currents. Rotating the horizontal records to the direction of the principle noise can largely suppress the principle noise in the orthogonal horizontal channel. In addition, the horizontal noise is incoherent with pressure, indicating that the noise source is not ocean surface water waves (infragravity waves). At some stations in shallow waters (<300 m), horizontal noise around 0.07 Hz is found to be linearly proportional to the temporal derivative of pressure, which is explained by forces of added mass due to infragravity waves.

The pP phase generated in water covered areas

1965 ◽  
Vol 55 (4) ◽  
pp. 721-726
Author(s):  
D. H. Shurbet
Keyword(s):  
North America ◽  
Crustal Structure ◽  
West Coast ◽  
Ocean Bottom ◽  
The West ◽  
Coefficient Of Reflection ◽  
Uppermost Layer ◽  
Epicenter Location

abstract The appearance of the pP phase, on seismograms, is strongly affected by the crustal structure in the vicinity of the epicenter. A recognizable pP phase is generated near the west coast of North America when the uppermost layer is water of sufficient depth. The generation of this pP is also affected by ocean bottom conditions. The bottom must probably be flat and the coefficient of reflection between the water and the bottom must be high. This pP phase may be useful in epicenter location and in crustal studies.

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