Local-Distance Seismic Event Relocation and Relative Magnitude Estimation, Applications to Mining Related Seismicity in the Powder River Basin, Wyoming

2021 ◽  
Author(s):  
Jonas A. Kintner ◽  
K. Michael Cleveland ◽  
Charles J. Ammon ◽  
Andrew Nyblade
Keyword(s):  
Relative Magnitude ◽  
Powder River Basin ◽  
Seismic Sources ◽  
Seismic Events ◽  
Explosion Monitoring ◽  
Location Uncertainty ◽  
Short Period ◽  
Uncertainty Estimates ◽  
Local Distance ◽  
Industrial Mining

ABSTRACT Recent efforts to characterize small (Mw<3) seismic events at local distances have become more important because of the increased observation of human-triggered and induced seismicity and the need to advance nuclear explosion monitoring capabilities. The signals generated by low-magnitude seismic sources necessitate the use of nearby short-period observations, which are sensitive to local geological heterogeneity. Local to near-regional distance (<300  km) surface and shear waves can dominate short-period observations from small, shallow seismic sources. In this work, we utilize these observations to estimate precise, relative locations and magnitudes of ∼700 industrial mining events in Wyoming, using nearly 360,000 observations. The precise, relative location estimates (with formal location uncertainty estimates of less than 1 km) collapse a diffuse collection of mining events into discrete clusters associated with individual blasting operations. We also invert the cross-correlation amplitudes to estimate precise, relative moment magnitude estimates, which help validate and identify disparities in the event sizes reported by regional network catalogs. Joint use of multiple phases allows for the inclusion of more seismic events due to the increase in the number of observations. In some cases, using a single phase allowed us to relocate only 50% of the original reported seismic events within a cluster. Combining shear- and surface-wave phases increased the number of events to above 90% of the original events, allowing us to characterize a broader range of event sizes, source to station distances, and event distributions. This analysis takes a step toward making a fuller characterization of small industrial seismic events observed at local distances.

Precise Relative Magnitude and Relative Location Estimates of Low-Yield Industrial Blasts in Pennsylvania

2020 ◽  
Vol 110 (1) ◽  
pp. 226-240
Author(s):  
Jonas A. Kintner ◽  
Charles J. Ammon ◽  
Kyle Homman ◽  
Andrew Nyblade
Keyword(s):  
Cross Correlation ◽  
Relative Magnitude ◽  
Time Shift ◽  
Relative Location ◽  
Mining Operations ◽  
Small Magnitude ◽  
Explosion Monitoring ◽  
Short Period ◽  
Local Shear ◽  
Seismic Networks

ABSTRACT Low-yield explosion monitoring requires the use of nearby short-period observations, which exhibit sensitivities to geologic heterogeneity and have low signal-to-noise ratios compared to larger events. In this study, we analyze 843 seismic events using nearly 475,000 individual observations to compute precise relative locations of small (1<ML<3) industrial explosions across Pennsylvania using local shear-wave and short-period, near-regional distance shear and surface-wave observations. We show that common-station, nearby event cross-correlation time-shift measurements reduce much of the complexity in wave propagation caused by regional geological heterogeneity. The resulting high-precision relative location estimates (with formal location uncertainties of tens of meters in some cases) allow us to image the time-dependent migration of the blast wall for several mines across Pennsylvania. In areas with two or more mines, the relative locations collapse a diffuse distribution of small-magnitude industrial events into discrete clusters associated with particular mining operations. We also use cross-correlation amplitudes to estimate more precise relative event magnitudes. We find that the relative magnitudes are generally consistent with the catalog magnitudes but improve the relationship between the reported amount of explosives used and event size for several mining operations throughout Pennsylvania. This work adds to existing demonstrations of how dense regional seismic networks are valuable for small-event monitoring and characterization, while also corroborating earlier works indicating the ability of cross-correlation methods to achieve precise relative location and magnituode estimates from local and regional observations of low-yield seismic sources.

scholarly journals OCAAT: automated analysis of star cluster colour-magnitude diagrams for gauging the local distance scale

2014 ◽  
Vol 10 (S306) ◽  
pp. 298-300
Author(s):  
Gabriel I. Perren ◽  
Ruben A. Vázquez ◽  
Andrés E. Piatti ◽  
André Moitinho
Keyword(s):  
Main Sequence ◽  
Star Clusters ◽  
Automated Analysis ◽  
Star Cluster ◽  
Magellanic Clouds ◽  
Distance Scale ◽  
Analysis Tool ◽  
Large Set ◽  
Uncertainty Estimates ◽  
Local Distance

AbstractStar clusters are among the fundamental astrophysical objects used in setting the local distance scale. Despite its crucial importance, the accurate determination of the distances to the Magellanic Clouds (SMC/LMC) remains a fuzzy step in the cosmological distance ladder. The exquisite astrometry of the recently launched ESA Gaia mission is expected to deliver extremely accurate statistical parallaxes, and thus distances, to the SMC/LMC. However, an independent SMC/LMC distance determination via main sequence fitting of star clusters provides an important validation check point for the Gaia distances. This has been a valuable lesson learnt from the famous Hipparcos Pleiades distance discrepancy problem. Current observations will allow hundreds of LMC/SMC clusters to be analyzed in this light.Today, the most common approach for star cluster main sequence fitting is still by eye. The process is intrinsically subjective and affected by large uncertainties, especially when applied to poorly populated clusters. It is also, clearly, not an efficient route for addressing the analysis of hundreds, or thousands, of star clusters. These concerns, together with a new attitude towards advanced statistical techniques in astronomy and the availability of powerful computers, have led to the emergence of software packages designed for analyzing star cluster photometry. With a few rare exceptions, those packages are not publicly available.Here we present OCAAT (Open Cluster Automated Analysis Tool), a suite of publicly available open source tools that fully automatises cluster isochrone fitting. The code will be applied to a large set of hundreds of open clusters observed in the Washington system, located in the Milky Way and the Magellanic Clouds. This will allow us to generate an objective and homogeneous catalog of distances up to ~ 60 kpc along with its associated reddening, ages and metallicities and uncertainty estimates.

scholarly journals Towards a standard typology of endogenous landslide seismic sources

2018 ◽  
Author(s):  
Floriane Provost ◽  
Jean-Philippe Malet ◽  
Clément Hibert ◽  
Agnès Helmstetter ◽  
Mathilde Radiguet ◽  
...  
Keyword(s):  
Seismic Activity ◽  
Seismic Waves ◽  
Surface Processes ◽  
Seismic Sources ◽  
Seismic Events ◽  
Earth Surface ◽  
Seismic Signals ◽  
Fluid Circulation ◽  
Source Mechanisms ◽  
Standard Classification

Abstract. In the last decade, numerous studies focused on the analysis of seismic waves generated by Earth surface processes such as landslides. The installation of seismometers on unstable slopes revealed a variety of seismic signals suspected to be generated by slope deformation, weathering of the slope material or fluid circulation. A standard classification for seismic sources generated by unstable slopes needs to be proposed in order to compare the seismic activity of several unstable slopes and identify possible correlation of the seismic activity rate with triggering factors. The objective of this work is to discuss the typology and source mechanisms of seismic events detected at close distances (

scholarly journals Further measurements on wireless waves received from the upper atmosphere

1927 ◽  
Vol 116 (775) ◽  
pp. 682-693 ◽  
Keyword(s):  
Closed Loop ◽  
Wave Length ◽  
Direct Proof ◽  
Relative Magnitude ◽  
Upper Atmosphere ◽  
Circle Plane ◽  
The Earth ◽  
Direction Finder ◽  
Short Period ◽  
Attention To Detail

In previous papers the authors have described the development of experimental methods of measuring the directions and relative intensities of both the electric and magnetic forces in wireless waves received at the earth’s surface from a distant transmitting station. In this work it was seen that the detection of the arrival of waves deflected from the upper atmosphere, and polarised with their electric force in a horizontal plane, was rendered difficult owing to the relatively great reflecting powTer of the earth resulting from its high conductivity. By a suitable choice of wave-length and careful attention to detail in the design and construction of the apparatus, however, the methods employed enabled measurements to be made on both vertically and horizontally polarised waves. The results of such measurements enabled a direct proof to be given of the fact that the fading of wireless signals on a vertical aerial and the variations of bearings experienced on the closed-loop type of wireless direction-finder are due to the reception respectively of vertically and horizontally polarised waves deflected from the upper atmosphere in their passage from the transmitter to the receiver. On arrival at the receiver, these indirect or atmospheric waves interfere with the direct or ground waves, in a manner determined by their relative magnitude and phase, and produce the intensity and apparent direc­tional variations mentioned above. The results of such interference phenomena have been investigated experimentally by Appleton and Barnett and by Holling-worth. In a more recent publication the present authors have provided experimental evidence showing that the path of the indirect waves is confined to the great circle plane between the transmitter and receiver. The measurements of the quantities in the received waves as previously described by the authors were confined to observations on the transmissions from the Bournemouth broadcasting station over a short period. The object of the present paper is to describe the continuation of these measurements and their extension to the transmissions from other stations.

scholarly journals Seismic activity on the territory of Slovakia in 2018

2019 ◽  
Vol 49 (4) ◽  
pp. 511-523
Author(s):  
Róbert Kysel ◽  
Andrej Cipciar ◽  
Kristián Csicsay ◽  
Lucia Fojtíková ◽  
Martin šugár ◽  
...  
Keyword(s):  
Seismic Activity ◽  
Earth Science ◽  
Routine Data ◽  
Seismic Events ◽  
Seismic Stations ◽  
National Network ◽  
Macroseismic Observations ◽  
The Earth ◽  
Short Period ◽  
Academy Of Sciences

Abstract The National Network of Seismic Stations of Slovakia (NNSS) consists of eight short period and five broadband permanent seismic stations and a data centre located at the Earth Science Institute of the Slovak Academy of Sciences (ESI SAS). The NNSS recorded and detected 11704 seismic events from all epicentral distances in 2018. Totally 86 earthquakes originated in the territory of Slovakia in 2018. This paper provides basic information on the configuration of the NNSS, routine data processing, seismic activity on the territory of Slovakia in 2018 as well as macroseismic observations collected in 2018.

scholarly journals Seismic activity on the territory of Slovakia in 2020

2021 ◽  
Vol 51 (4) ◽  
pp. 373-389
Author(s):  
Róbert KYSEL ◽  
Andrej CIPCIAR ◽  
Martin ŠUGÁR ◽  
Kristián CSICSAY ◽  
Lucia FOJTÍKOVÁ ◽  
...  
Keyword(s):  
Seismic Activity ◽  
Earth Science ◽  
Routine Data ◽  
Seismic Events ◽  
Seismic Stations ◽  
National Network ◽  
Macroseismic Observations ◽  
The Earth ◽  
Short Period ◽  
Academy Of Sciences

The National Network of Seismic Stations of Slovakia (NNSS) consists of eight short period and six broadband permanent seismic stations and a data centre located at the Earth Science Institute of the Slovak Academy of Sciences (ESI SAS). The NNSS recorded and detected 11229 seismic events from all epicentral distances in 2020. Totally 96 earthquakes originated in the territory of Slovakia in 2020. This paper provides basic information on the configuration of the NNSS, routine data processing, seismic activity on the territory of Slovakia in 2020 as well as macroseismic observations collected in 2020.

scholarly journals Correlation between seismicity and barometric tidal exalting

2008 ◽  
Vol 8 (5) ◽  
pp. 1129-1137 ◽  
Author(s):  
D. N. Arabelos ◽  
G. Asteriadis ◽  
A. Bloutsos ◽  
M. E. Contadakis ◽  
S. D. Spatalas
Keyword(s):  
Barometric Pressure ◽  
Data Block ◽  
Seismic Events ◽  
Northern Greece ◽  
Time Intervals ◽  
Tidal Waves ◽  
Short Period ◽  
Time Periods ◽  
One Year ◽  
The One

Abstract. Changes of barometric pressure in the area of Thessaloniki in Northern Greece were studied by analyzing a sample of 31 years of hourly measurements. The results of this analysis on the periodicities of tidal components are expressed in terms of amplitude and phases variability. An earlier investigation revealed a detectable correlation between the exalting of the amplitude parameters of the tidal waves with strong seismic events. A problem of this work was that we had compared the tidal parameters resulting from the analysis of data covering the period of one year with instantaneous seismic events, although the earthquake is the final result of a tectonic process of the upper lithosphere. Consequently, in order to increase the resolution of our method we had analyzed our data in groups of 3-months extent and the resulted amplitudes were compared with seismicity index for corresponding time periods. A stronger correlation was found in the last case. However, the estimation of tidal parameters in this case was restricted to short period (from one day down to eight hours) constituents. Therefore, a new analysis was performed, retaining the one-year length of each data block but shifting the one year window by steps of three months from the beginning to the end of the 31 years period. This way, we are able to estimate again tidal parameters ranging from periods of one year (Sa) down to eight hours (M3). The resulting correlation between these tidal parameters with a cumulative seismicity index for corresponding time intervals was remarkably increased.

scholarly journals Structure of the Suasselkä postglacial fault in northern Finland obtained by analysis of local events and ambient seismic noise

Solid Earth ◽  
2017 ◽  
Vol 8 (2) ◽  
pp. 531-544 ◽  
Author(s):  
Nikita Afonin ◽  
Elena Kozlovskaya ◽  
Ilmo Kukkonen ◽  
Keyword(s):  
Seismic Noise ◽  
Ambient Seismic Noise ◽  
Seismic Events ◽  
S Wave ◽  
Noise Sources ◽  
Surface Wave Dispersion ◽  
Velocity Models ◽  
Wave Velocities ◽  
Short Period ◽  
Single Station

Abstract. Understanding the inner structure of seismogenic faults and their ability to reactivate is particularly important in investigating the continental intraplate seismicity regime. In our study we address this problem using analysis of local seismic events and ambient seismic noise recorded by the temporary DAFNE array in the northern Fennoscandian Shield. The main purpose of the DAFNE/FINLAND passive seismic array experiment was to characterize the present-day seismicity of the Suasselkä postglacial fault (SPGF), which was proposed as one potential target for the DAFNE (Drilling Active Faults in Northern Europe) project. The DAFNE/FINLAND array comprised an area of about 20 to 100 km and consisted of eight short-period and four broadband three-component autonomous seismic stations installed in the close vicinity of the fault area. The array recorded continuous seismic data during September 2011–May 2013. Recordings of the array have being analysed in order to identify and locate natural earthquakes from the fault area and to discriminate them from the blasts in the Kittilä gold mine. As a result, we found a number of natural seismic events originating from the fault area, which proves that the fault is still seismically active. In order to study the inner structure of the SPGF we use cross-correlation of ambient seismic noise recorded by the array. Analysis of azimuthal distribution of noise sources demonstrated that during the time interval under consideration the distribution of noise sources is close to the uniform one. The continuous data were processed in several steps including single-station data analysis, instrument response removal and time-domain stacking. The data were used to estimate empirical Green's functions between pairs of stations in the frequency band of 0.1–1 Hz and to calculate corresponding surface wave dispersion curves. The S-wave velocity models were obtained as a result of dispersion curve inversion. The results suggest that the area of the SPGF corresponds to a narrow region of low S-wave velocities surrounded by rocks with high S-wave velocities. We interpret this low-velocity region as a non-healed mechanically weak fault damage zone (FDZ) formed due to the last major earthquake that occurred after the last glaciation.

scholarly journals Sculpting the valley in the radius distribution of small exoplanets as a by-product of planet formation: the core-powered mass-loss mechanism

2019 ◽  
Vol 487 (1) ◽  
pp. 24-33 ◽  
Author(s):  
Akash Gupta ◽  
Hilke E Schlichting
Keyword(s):  
Mass Loss ◽  
Thermal Evolution ◽  
Relative Magnitude ◽  
Occurrence Rate ◽  
Loss Mechanism ◽  
Water Ice ◽  
The Core ◽  
Planetary Cores ◽  
Short Period ◽  
Atmospheric Mass

ABSTRACT Recent observations revealed a bimodal radius distribution of small, short-period exoplanets with a paucity in their occurrence, a radius ‘valley’, around 1.5–2.0 R⊕. In this work, we investigate the effect of a planet’s own cooling luminosity on its thermal evolution and atmospheric mass loss (core-powered mass-loss) and determine its observational consequences for the radius distribution of small, close-in exoplanets. Using simple analytical descriptions and numerical simulations, we demonstrate that planetary evolution based on the core-powered mass-loss mechanism alone (i.e. without any photoevaporation) can produce the observed valley in the radius distribution. Our results match the valley’s location, shape and slope in planet radius–orbital period parameter space, and the relative magnitudes of the planet occurrence rate above and below the valley. We find that the slope of the valley is, to first order, dictated by the atmospheric mass-loss time-scale at the Bondi radius and given by d logRp/d logP ≃ 1/(3(1 − β)) that evaluates to −0.11 for β ≃ 4, where Mc/M⊕ = (Rc/R⊕)β(ρc∗/ρ⊕)β/3 is the mass–radius relation of the core. This choice for β yields good agreement with observations and attests to the significance of internal compression for massive planetary cores. We further find that the location of the valley scales as $\rho _{\rm c*}^{-4/9}$ and that the observed planet population must have predominantly rocky cores with typical water–ice fractions of less than ${\sim } 20{{\, \rm per\, cent}}$. Furthermore, we show that the relative magnitude of the planet occurrence rate above and below the valley is sensitive to the details of the planet-mass distribution but that the location of the valley is not.

Radiation patterns: Possibility for monitoring seismic sources

Geophysics ◽  
1996 ◽  
Vol 61 (1) ◽  
pp. 282-287
Author(s):  
Philip Carrion ◽  
José Carcione ◽  
Edson E. S. Sampaio
Keyword(s):  
Point Source ◽  
Field Measurements ◽  
Seismic Sources ◽  
Seismic Events ◽  
Elastic Media ◽  
Radiation Patterns ◽  
Source Radiation ◽  
Earth Environment ◽  
Source Excitation ◽  
Homogeneous Media

Recent field measurements of the radiation in boreholes indicate that the radiation patterns of real seismic sources are not always in agreement with those corresponding to the point‐source excitation in unbounded homogeneous and isotropic acoustic or elastic media [we refer the reader to Aki and Richards (1980) for the basic discussion on the radiation patterns in homogeneous media]. This mismatch results from the fact that the point‐source radiation patterns corresponding to homogeneous media are too simplistic to satisfy any experiment in the more realistic Earth environment. A study of radiation patterns is certainly important not only to predict possible seismic events but also to analyze the source performance itself by recording seismic arrivals.

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