Spatial analysis for an evaluation of monitoring networks: examples from the Italian seismic and accelerometric networks

AbstractIn this work, we propose a statistical approach to evaluate the coverage of a network based on the spatial distribution of its nodes and the target information, including all those data related to the final objectives of the network itself. This statistical approach encompasses descriptive spatial statistics in combination with point pattern techniques. As case studies, we evaluate the spatial arrangements of the stations within the Italian National Seismic Network and the Italian Strong Motion Network. Seismic networks are essential tools for observing earthquakes and assessing seismic hazards, while strong motion (accelerometric) networks allow us to describe seismic shaking and to measure the expected effects on buildings and infrastructures. The capability of both networks is a function of an adequate number of optimally distributed stations. We compare the seismic network with the spatial distributions of historical and instrument seismicity and with the distribution of well-known seismogenic sources, and we compare the strong motion station distribution with seismic hazard maps and the population distribution. This simple and reliable methodological approach is able to provide quantitative information on the coverage of any type of network and is able to identify critical areas that require optimization and therefore address areas of future development.

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Comparison of Coseismic Displacement Obtained from GEONET and Seismic Networks

Journal of Earthquake and Tsunami ◽

10.1142/s1793431116400029 ◽

2016 ◽

Vol 10 (02) ◽

pp. 1640002 ◽

Cited By ~ 2

Author(s):

Luis Moya ◽

Fumio Yamazaki ◽

Wen Liu

Keyword(s):

Global Positioning System ◽

Strong Motion ◽

Search Method ◽

Baseline Correction ◽

Positioning System ◽

Coseismic Displacement ◽

Strong Motion Station ◽

Global Positioning ◽

Gps Networks ◽

Seismic Networks

It is generally recognized that permanent displacements estimated by the double integration of acceleration records need a suitable baseline correction. Current baseline correction methods have been validated by comparing the displacements with those from the Global Positioning System (GPS) records nearby, but GPS stations that are sufficiently close to a strong-motion station are scarce. Because the [Formula: see text] Tohoku-Oki earthquake produced geodetic displacements in a wide area and because dense strong-motion and GPS networks are available in Japan, we interpolated the displacements calculated from GPS records to estimate the permanent displacements at 508 strong-motion stations. The estimated results were used to evaluate uncertainties in permanent displacements obtained using two baseline correction methods, and results were found to be reliable only for KiK-net’s borehole acceleration records. A new joint parameter search method for the surface and borehole records was further proposed, and reliable results were obtained for KiK-net’s surface records.

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Estimation of seismic network detection thresholds for Austria

10.5194/egusphere-egu2020-21693 ◽

2020 ◽

Author(s):

Maria-Theresia Apoloner ◽

Helmut Hausmann ◽

Nikolaus Horn ◽

Keyword(s):

Strong Motion ◽

Low Noise ◽

Seismic Network ◽

Detection Thresholds ◽

Infrastructure Monitoring ◽

Cross Border ◽

Detection Capabilities ◽

Set Up ◽

Seismic Networks ◽

Different Sources

Seismic networks are expanding and changing continuously: station instrumentation breaks and improves, new stations are set up permanently and temporarily for projects, or get available online from seismological services. For routine processing, it is important to know&#160;if and&#160;where&#160;adding an existing station to processing or building or improving a station will add the most value to the detection an location capabilities.Therefore, in this study we calculate&#160;seismic network detectionthresholds for Austria using&#160;data available&#160;to us&#160;from different sources: From the&#160;Seismic Network of Austria (OE), which consists of&#160;unevenly distributed&#160;high quality low noise broadband and strong-motion stations, with station spacing up to 100 km.&#160;Cross-border&#160;from neighboring countries, where each of them operates at least one seismic network with very different station quality and coverage.&#160;As well as from temporary&#160;regional scientific projects (i.a. AlpArray (Z3), the SWATH (ZS)) and local infrastructure monitoring&#160;(GeoTief EXPLORE 3D).Additionally to comparing different methods&#160;(SN-CAST by M&#246;llhoff et al. 2019, Net-Sim by Niko Horn, GT5-criterium)&#160;with each other,&#160;we also analyze how strong-motion stations, recently added due to&#160;the&#160;interregio project ARMONIA,&#160;improve&#160;the detection capabilities.

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Elastic displacements in the near-field of a propagating fault

Bulletin of the Seismological Society of America ◽

10.1785/bssa0590020865 ◽

1969 ◽

Vol 59 (2) ◽

pp. 865-908

Author(s):

N. A. Haskell

Keyword(s):

Fault Plane ◽

Near Field ◽

Strong Motion ◽

Dislocation Motion ◽

Displacement Discontinuity ◽

Wave Form ◽

Strong Motion Station ◽

Ramp Function ◽

Wave Forms ◽

Parkfield Earthquake

abstract Displacement, particle velocity, and acceleration wave forms in the near field of a propagating fault have been computed by numerical integration of the Green's function integrals for an infinite medium. The displacement discontinuity (dislocation) on the fault plane is assumed to have the form of a unilaterally propagating finite ramp function in time. The calculated wave forms in the vicinity of the fault plane are quite similar to those observed at the strong motion station nearest the fault plane at the Parkfield earthquake. The comparison suggests that the propagating ramp time function is roughly representative of the main features of the dislocation motion on the fault plane, but that the actual motion has somewhat more high frequency complexity. Calculated amplitudes indicate that the average final dislocation on the fault at the Parkfield earthquake was more than an order of magnitude greater than the offsets observed on the visible surface trace. Computer generated wave form plots are presented for a variety of locations with respect to the fault plane and for two different assumptions on the relation between fault length and ramp function duration.

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Evolution of the Kandilli Observatory and Earthquake Research Institute (KOERI) Seismic Network and the Data Center Facilities as a Primary Node of EIDA

Seismological Research Letters ◽

10.1785/0220200367 ◽

2021 ◽

Author(s):

Musavver Didem Cambaz ◽

Mehmet Özer ◽

Yavuz Güneş ◽

Tuğçe Ergün ◽

Zafer Öğütcü ◽

...

Keyword(s):

Data Center ◽

Strong Motion ◽

Seismic Network ◽

Data Archive ◽

Seismic Stations ◽

Earthquake Research ◽

Earthquake Research Institute ◽

Research Facilities ◽

Research Institute

Abstract As the earliest institute in Turkey dedicated to locating, recording, and archiving earthquakes in the region, the Kandilli Observatory and Earthquake Research Institute (KOERI) has a long history in seismic observation, which dates back to the installation of its first seismometers soon after the devastating Istanbul earthquake of 10 July 1894. For over a century, since the deployment of its first seismometer, the KOERI seismic network has grown steadily in time. In this article, we present the KOERI seismic network facilities as a data center for the seismological community, providing data and services through the European Integrated Data Archive (EIDA) and the Rapid Raw Strong-Motion (RRSM) database, both integrated in the Observatories and Research Facilities for European Seismology (ORFEUS). The objective of this article is to provide an overview of the KOERI seismic services within ORFEUS and to introduce some of the procedures that allow to check the health of the seismic network and the quality of the data recorded at KOERI seismic stations, which are shared through EIDA and RRSM.

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Analysis of debris-flow recordings in an instrumented basin: confirmations and new findings

Natural Hazards and Earth System Science ◽

10.5194/nhess-12-679-2012 ◽

2012 ◽

Vol 12 (3) ◽

pp. 679-686 ◽

Cited By ~ 27

Author(s):

M. Arattano ◽

L. Marchi ◽

M. Cavalli

Keyword(s):

Debris Flow ◽

Alluvial Fan ◽

Seismic Network ◽

Low Flow ◽

Main Peak ◽

Flow Monitoring ◽

Irregular Pattern ◽

New Findings ◽

Seismic Recording ◽

Seismic Networks

Abstract. On 24 August 2006, a debris flow took place in the Moscardo Torrent, a basin of the Eastern Italian Alps instrumented for debris-flow monitoring. The debris flow was recorded by two seismic networks located in the lower part of the basin and on the alluvial fan, respectively. The event was also recorded by a pair of ultrasonic sensors installed on the fan, close to the lower seismic network. The comparison between the different recordings outlines particular features of the August 2006 debris flow, different from that of events recorded in previous years. A typical debris-flow wave was observed at the upper seismic network, with a main front abruptly appearing in the torrent, followed by a gradual decrease of flow height. On the contrary, on the alluvial fan the wave displayed an irregular pattern, with low flow depth and the main peak occurring in the central part of the surge both in the seismic recording and in the hydrographs. Recorded data and field evidences indicate that the surge observed on the alluvial fan was not a debris flow, and probably consisted in a water surge laden with fine to medium-sized sediment. The change in shape and characteristics of the wave can be ascribed to the attenuation of the surge caused by the torrent control works implemented in the lower basin during the last years.

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Real-time seismology at UC Berkeley: The Rapid Earthquake Data Integration project

Bulletin of the Seismological Society of America ◽

10.1785/bssa0860040936 ◽

1996 ◽

Vol 86 (4) ◽

pp. 936-945 ◽

Cited By ~ 2

Author(s):

Lind S. Gee ◽

Douglas S. Neuhauser ◽

Douglas S. Dreger ◽

Michael E. Pasyanos ◽

Robert A. Uhrhammer ◽

...

Keyword(s):

Data Integration ◽

Strong Motion ◽

Seismic Network ◽

Prototype System ◽

Earthquake Parameters ◽

Moment Tensors ◽

Automatic Information ◽

Integration Project ◽

Earthquake Data

Abstract The Rapid Earthquake Data Integration project is a system for the fast determination of earthquake parameters in northern and central California based on data from the Berkeley Digital Seismic Network and the USGS Northern California Seismic Network. Program development started in 1993, and a prototype system began providing automatic information on earthquake location and magnitude in November of 1993 via commercial pagers and the Internet. Recent enhancements include the exchange of phase data with neighboring networks and the inauguration of processing for the determination of strong-motion parameters and seismic moment tensors.

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2019 Ridgecrest Earthquake Reveals Areas of Los Angeles That Amplify Shaking of High-Rises

Seismological Research Letters ◽

10.1785/0220200170 ◽

2020 ◽

Vol 91 (6) ◽

pp. 3370-3380

Author(s):

Monica D. Kohler ◽

Filippos Filippitzis ◽

Thomas Heaton ◽

Robert W. Clayton ◽

Richard Guy ◽

...

Keyword(s):

Los Angeles ◽

Strong Motion ◽

Ground Level ◽

Site Amplification ◽

Seismic Network ◽

Los Angeles Basin ◽

High Rise ◽

The North ◽

South Central ◽

San Fernando

Abstract The populace of Los Angeles, California, was startled by shaking from the M 7.1 earthquake that struck the city of Ridgecrest located 200 km to the north on 6 July 2019. Although the earthquake did not cause damage in Los Angeles, the experience in high-rise buildings was frightening in contrast to the shaking felt in short buildings. Observations from 560 ground-level accelerometers reveal large variations in shaking in the Los Angeles basin that occurred for more than 2 min. The observations come from the spatially dense Community Seismic Network (CSN), combined with the sparser Southern California Seismic Network and California Strong Motion Instrumentation Program networks. Site amplification factors for periods of 1, 3, 6, and 8 s are computed as the ratio of each station’s response spectral values combined for the two horizontal directions, relative to the average of three bedrock sites. Spatially coherent behavior in site amplification emerges for periods ≥3 s, and the maximum calculated site amplifications are the largest, by factors of 7, 10, and 8, respectively, for 3, 6, and 8 s periods. The dense CSN observations show that the long-period amplification is clearly, but only partially, correlated with the depth to basement. Sites with the largest amplifications for the long periods (≥3 s) are not close to the deepest portion of the basin. At 6 and 8 s periods, the maximum amplifications occur in the western part of the Los Angeles basin and in the south-central San Fernando Valley sedimentary basin. The observations suggest that the excitation of a hypothetical high-rise located in an area characterized by the largest site amplifications could be four times larger than in a downtown Los Angeles location.

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A review of methods for estimating the contribution of glacial meltwater to total watershed discharge

Progress in Physical Geography Earth and Environment ◽

10.1177/0309133313516161 ◽

2014 ◽

Vol 38 (2) ◽

pp. 173-200 ◽

Cited By ~ 42

Author(s):

Jeff La Frenierre ◽

Bryan G. Mark

Keyword(s):

Hydrological Modeling ◽

Methodological Approach ◽

Future Research ◽

Monitoring Networks ◽

Watershed Hydrology ◽

Glacial Meltwater ◽

Natural Systems ◽

Meltwater Runoff ◽

Proportional Contribution

Glaciers store water over a range of temporal scales with important implications for downstream human and natural systems. Assessment of the contribution of glacial meltwater runoff to total watershed discharge is an essential part of climate change risk assessment and sustainable water management in glacierized watersheds. Over the past decade, a range of techniques for quantifying the proportional contribution of glacial meltwater has been presented in the scientific literature. Here we examine five different methodological approaches: direct discharge measurement, glaciological approaches, hydrological balance equations, hydrochemical tracers, and hydrological modeling. After a brief summary of the role of glaciers in watershed hydrology, we evaluate each approach, with regard to their respective data requirements, assumptions, and associated uncertainties. Next, we discuss factors that researchers must consider in deciding upon a particular methodological approach, then conclude with a discussion of future research needs. We underscore the need for expanded meteorological, hydrological, and glaciological monitoring networks in glacierized watersheds worldwide, for more comprehensive assessment of uncertainty and for better integration of research with the specific needs of watershed stakeholders.

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A Methodological Approach to Radical Technological Changes and Improvements in Electron Beam Technology

ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, Volume 4 ◽

10.1115/esda2010-24610 ◽

2010 ◽

Author(s):

Marco Cavallaro ◽

Giovanni Moroni ◽

Michael Zaeh ◽

Stefan Lutzmann ◽

Markus Kahnert

Keyword(s):

Decision Making ◽

Electron Beam ◽

Statistical Approach ◽

Methodological Approach ◽

Dimensional Accuracy ◽

Rapid Manufacturing ◽

Manufacturing Processes ◽

Technological Changes ◽

Integrated Methodology ◽

Influencing Parameters

Predicting of the optimal machining conditions for experimental results and dimensional accuracy plays an important role in process planning. In addition, whenever there is a new unknown process, great importance has to be placed on the estimation of all operative conditions with rational and logical planning methodologies. The aim of this work is to obtain feasible conditions for Electron Beam (EB) technology, using a welding machine, which is then converted for additive manufacturing processes. At the beginning of the research there was a state of uncertainty about the influencing parameters and the use of EB for rapid manufacturing process; a multi-disciplinary and integrated methodology was then performed in order to carry out the work. The proposed methodology is composed of several techniques, including a method to support multi-decision making problems and a statistical approach.

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Effect of Combining Catalogs with Different Completeness

10.5194/egusphere-egu2020-1749 ◽

2020 ◽

Author(s):

Myunghyun Noh

Keyword(s):

Korean Peninsula ◽

North Korea ◽

Seismic Network ◽

The Other ◽

Earthquake Catalog ◽

Detection Capability ◽

Chi Square ◽

Earthquake Detection ◽

Seismic Networks ◽

Target Monitoring

In most seismic studies, we prefer the earthquake catalog that covers a larger region and/or a longer period. We usually combine two or more catalogs to achieve this goal. When combining catalogs, however, care must be taken because their completeness is not identical so that unexpected flaws may be caused.We tested the effect of combining inhomogeneous catalogs using the catalog of Korea Meteorological Administration (KMA). In fact, KMA provides a single catalog containing the earthquakes occurred in and around the whole Korean Peninsula. Like the other seismic networks, however, the configuration of the KMA seismic network is not uniform over its target monitoring region, so is the earthquake detection capability. The network is denser in the land than in the off-shore. Moreover, there are no seismic information available from North Korea. Based on these, we divided the KMA catalog into three sub-catalogs; SL, NL, and AO catalogs. The SL catalog contains the earthquakes occurred in the land of South Korea while the NL catalog contains those in the land of North Korea. The AO catalog contains all earthquakes occurred in the off-shore surrounding the peninsula.The completeness of a catalog is expressed in terms of mc, the minimum magnitude above which no earthquakes are missing. We used the Chi-square algorithm by Noh (2017) to estimate the mc. It turned out, as expected, that the mc of the SL is the smallest among the three. Those of NL and AO are comparable. The mc of the catalog combining the SL and AO is larger than those of individual catalogs before combining. The mc is largest when combining all the three. If one needs more complete catalog, he or she had better divide the catalog into smaller ones based on the spatiotemporal detectability of the seismic network. Or, one may combine several catalogs to cover a larger region or a longer period at the expense of catalog completeness.

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