scholarly journals A Plan for a Long-Term, Automated, Broadband Seismic Monitoring Network on the Global Seafloor

2020 ◽  
Vol 91 (3) ◽  
pp. 1343-1355
Author(s):  
Monica D. Kohler ◽  
Katrin Hafner ◽  
Jeffrey Park ◽  
Jessica C. E. Irving ◽  
Jackie Caplan-Auerbach ◽  
...  
Keyword(s):  
Seismic Station ◽  
Monitoring Network ◽  
Rechargeable Batteries ◽  
Ocean Bottom ◽  
Tectonic Structures ◽  
Seismic Stations ◽  
Pilot Experiment ◽  
Earth’S Interior ◽  
Earth's Interior

Abstract Establishing an extensive and highly durable, long-term, seafloor network of autonomous broadband seismic stations to complement the land-based Global Seismographic Network has been a goal of seismologists for decades. Seismic signals, chiefly the vibrations from earthquakes but also signals generated by storms and other environmental processes, have been processed from land-based seismic stations to build intriguing but incomplete images of the Earth’s interior. Seismologists have mapped structures such as tectonic plates and other crustal remnants sinking deep into the mantle to obtain information on their chemical composition and physical state; but resolution of these structures from land stations is not globally uniform. Because the global surface is two-thirds ocean, increasing the number of seismic stations located in the oceans is critical for better resolution of the Earth’s interior and tectonic structures. A recommendation for a long-term seafloor seismic station pilot experiment is presented here. The overarching instrumentation goal of a pilot experiment is performance that will lead to the installation of a large number of long-term autonomous ocean-bottom seismic stations. The payoff of a network of stations separated from one another by a few hundred kilometers under the global oceans would be greatly refined resolution of the Earth’s interior at all depths. A second prime result would be enriched understanding of large-earthquake rupture processes in both oceanic and continental plates. The experiment would take advantage of newly available technologies such as robotic wave gliders that put an affordable autonomous prototype within reach. These technologies would allow data to be relayed to satellites from seismometers that are deployed on the seafloor with long-lasting, rechargeable batteries. Two regions are presented as promising arenas for such a prototype seafloor seismic station. One site is the central North Atlantic Ocean, and the other high-interest locale is the central South Pacific Ocean.

scholarly journals Geosystemics View of Earthquakes

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 412 ◽  
Author(s):  
Angelo De Santis ◽  
Cristoforo Abbattista ◽  
Lucilla Alfonsi ◽  
Leonardo Amoruso ◽  
Saioa A. Campuzano ◽  
...  
Keyword(s):  
Solid Earth ◽  
Point Of View ◽  
Satellite Observations ◽  
Earth System ◽  
Seismic Sequences ◽  
The Earth ◽  
Earth’S Interior ◽  
Earth's Interior ◽  
Physical Quantities

Earthquakes are the most energetic phenomena in the lithosphere: their study and comprehension are greatly worth doing because of the obvious importance for society. Geosystemics intends to study the Earth system as a whole, looking at the possible couplings among the different geo-layers, i.e., from the earth’s interior to the above atmosphere. It uses specific universal tools to integrate different methods that can be applied to multi-parameter data, often taken on different platforms (e.g., ground, marine or satellite observations). Its main objective is to understand the particular phenomenon of interest from a holistic point of view. Central is the use of entropy, together with other physical quantities that will be introduced case by case. In this paper, we will deal with earthquakes, as final part of a long-term chain of processes involving, not only the interaction between different components of the Earth’s interior but also the coupling of the solid earth with the above neutral or ionized atmosphere, and finally culminating with the main rupture along the fault of concern. Particular emphasis will be given to some Italian seismic sequences.

scholarly journals SISMIKO: emergency network deployment and data sharing for the 2016 central Italy seismic sequence

2016 ◽  
Vol 59 ◽  
Author(s):  
Milena Moretti ◽  
Silvia Pondrelli ◽  
Lucia Margheriti ◽  
Luigi Abruzzese ◽  
Mario Anselmi ◽  
...  
Keyword(s):  
Seismic Station ◽  
Central Italy ◽  
Strong Motion ◽  
Monitoring Network ◽  
Seismic Monitoring ◽  
Seismic Network ◽  
Seismic Sequence ◽  
British Geological Survey ◽  
Epicentral Area ◽  
Seismic Stations

<p>At 01:36 UTC (03:36 local time) on August 24th 2016, an earthquake Mw 6.0 struck an extensive sector of the central Apennines (coordinates: latitude 42.70° N, longitude 13.23° E, 8.0 km depth). The earthquake caused about 300 casualties and severe damage to the historical buildings and economic activity in an area located near the borders of the Umbria, Lazio, Abruzzo and Marche regions. The Istituto Nazionale di Geofisica e Vulcanologia (INGV) located in few minutes the hypocenter near Accumoli, a small town in the province of Rieti. In the hours after the quake, dozens of events were recorded by the National Seismic Network (Rete Sismica Nazionale, RSN) of the INGV, many of which had a ML &gt; 3.0. The density and coverage of the RSN in the epicentral area meant the epicenter and magnitude of the main event and subsequent shocks that followed it in the early hours of the seismic sequence were well constrained. However, in order to better constrain the localizations of the aftershock hypocenters, especially the depths, a denser seismic monitoring network was needed. Just after the mainshock, SISMIKO, the coordinating body of the emergency seismic network at INGV, was activated in order to install a temporary seismic network integrated with the existing permanent network in the epicentral area. From August the 24th to the 30th, SISMIKO deployed eighteen seismic stations, generally six components (equipped with both velocimeter and accelerometer), with thirteen of the seismic station transmitting in real-time to the INGV seismic monitoring room in Rome. The design and geometry of the temporary network was decided in consolation with other groups who were deploying seismic stations in the region, namely EMERSITO (a group studying site-effects), and the emergency Italian strong motion network (RAN) managed by the National Civil Protection Department (DPC). Further 25 BB temporary seismic stations were deployed by colleagues of the British Geological Survey (BGS) and the School of Geosciences, University of Edinburgh in collaboration with INGV. All data acquired from SISMIKO stations, are quickly available at the European Integrated Data Archive (EIDA). The data acquired by the SISMIKO stations were included in the preliminary analysis that was performed by the Bollettino Sismico Italiano (BSI), the Centro Nazionale Terremoti (CNT) staff working in Ancona, and the INGV-MI, described below.</p>

How well do we utilize global seismicity?

1996 ◽  
Vol 86 (5) ◽  
pp. 1207-1219
Author(s):  
Michael E. Wysession
Keyword(s):  
Epicentral Distance ◽  
Ocean Bottom ◽  
Digital Networks ◽  
The Earth ◽  
Large Numbers ◽  
Ocean Bottom Seismometers ◽  
History Of ◽  
Global Seismicity ◽  
Earth’S Interior ◽  
Earth's Interior

Abstract This article describes a method for quantifying the ability to record teleseismic phases at particular epicentral distance ranges, given the geographical history of global seismicity. With the use of geographical sampling maps, we identify the regions of the Earth that are best suited to record the greatest numbers of earthquakes at particular distances. Since seismic studies of the Earth's interior use teleseismic phases that have unique ranges, this information can be useful in the planning of future permanent and temporary deployments of seismometers. Deployment of ocean-bottom seismometers would be required for recording large numbers of earthquakes in the 40° to 80° range, corresponding to phases like ScS and PcP, and in the 140° to 170° range, important for investigations of the PKP branches. An examination of existing analog and digital networks shows that they do either better or worse than a hypothetical grid of evenly spaced seismometers, depending upon the distance range examined. The use of temporary deployments of seismometers, perhaps even in the oceans, may be the best way to significantly sample poorly examined regions of the Earth's interior.

scholarly journals Earthquake location in tectonic structures of the Alpine Chain: the case of the Constance Lake (Central Europe) seismic sequence

2021 ◽  
Author(s):  
Francesca D’Ajello Caracciolo ◽  
Rodolfo Console
Keyword(s):  
Central Europe ◽  
Velocity Model ◽  
Moho Depth ◽  
Seismic Sequence ◽  
Tectonic Structures ◽  
Study Region ◽  
Waveform Data ◽  
Seismic Stations ◽  
Velocity Models ◽  
Master Event

AbstractA set of four magnitude Ml ≥ 3.0 earthquakes including the magnitude Ml = 3.7 mainshock of the seismic sequence hitting the Lake Constance, Southern Germany, area in July–August 2019 was studied by means of bulletin and waveform data collected from 86 seismic stations of the Central Europe-Alpine region. The first single-event locations obtained using a uniform 1-D velocity model, and both fixed and free depths, showed residuals of the order of up ± 2.0 s, systematically affecting stations located in different areas of the study region. Namely, German stations to the northeast of the epicenters and French stations to the west exhibit negative residuals, while Italian stations located to the southeast are characterized by similarly large positive residuals. As a consequence, the epicentral coordinates were affected by a significant bias of the order of 4–5 km to the NNE. The locations were repeated applying a method that uses different velocity models for three groups of stations situated in different geological environments, obtaining more accurate locations. Moreover, the application of two methods of relative locations and joint hypocentral determination, without improving the absolute location of the master event, has shown that the sources of the four considered events are separated by distances of the order of one km both in horizontal coordinates and in depths. A particular attention has been paid to the geographical positions of the seismic stations used in the locations and their relationship with the known crustal features, such as the Moho depth and velocity anomalies in the studied region. Significant correlations between the observed travel time residuals and the crustal structure were obtained.

Materials Science of the Earth's Interior

Eos ◽  
1985 ◽  
Vol 66 (34) ◽  
pp. 605
Author(s):  
Motoaki Sato
Keyword(s):  
Materials Science ◽  
Earth’S Interior ◽  
Earth's Interior
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