scholarly journals KAJI-SAIEARTHQUAKEonNovember 14, 2014 withКР=13.7, Mw=5.4, I0=7 (Kyrgyzstan, SouthernIssyk-Kul’)

2020 ◽  
pp. 364-374
Author(s):  
V. Grebennikova ◽  
A. Frolova ◽  
N. Bagmanova ◽  
A. Berezina ◽  
A. Pershina ◽  
...  
Keyword(s):  
Main Shock ◽  
Weather Conditions ◽  
Reverse Fault ◽  
Depth Range ◽  
Southern Coast ◽  
Epicentral Zone ◽  
Isoseismal Map ◽  
Fault Type ◽  
Macroseismic Survey ◽  
H 20

Information on the earthquake with Mw=5.4 that occurred on the southern coast of the Issyk-Kul lake on the southwestern slope of the Tegerek mountains (Kyrgyzstan) on November 14, 2014 is given. The epicenter is located in the Jumgalo-Terskey zone, identified as the Tonsky block, in which felt earthquakes with intensity up to 7 have occurred repeatedly. 231 aftershocks were recorded in the first day, in the second day – 13 aftershocks, then seismic activity decreased. Most of the aftershocks are localized in the depth range of 17–21 km, close to the depth of the main shock (h=20 km). The earthquake had the reverse fault type. Macroseismic survey was fulfilled only in the epicentral zone due to the complex weather conditions (late autumn, highlands). The theoretical isoseismal map was created for receiving the more complete picture of the earthquake impact outside of its epicentral zone.

The strong earthquake of 26 November 2019 (MW6.4) and its associate active tectonic of Durresi Region in Albania.

2020 ◽  
Author(s):  
Rrapo Ormeni ◽  
Ismail Hoxha ◽  
Petraq Naco ◽  
Dashi Gego
Keyword(s):  
Urban Areas ◽  
Strong Earthquake ◽  
Main Shock ◽  
Adriatic Sea ◽  
River Estuary ◽  
Capital City ◽  
Seismogenic Zone ◽  
Reverse Fault ◽  
Epicentral Zone ◽  
River Bed

<p>On November 26, 2019, a strong earthquake (Mw6.4) occurred about 16 km, north of the Durresi city in the Adriatic Sea, and 35 km NW from the capital city of Tirana, in the western part of Albania. The main shock of November 26 at 15:20 (UTC) was followed by a great number of aftershocks.<br>The main event is not a shallow one, with the hypocentral depth at 39 km. This fact explains the localized destruction, not only in the epicentral zone but in a larger zone. This earthquake expresses the increase of recently seismic activity of the Adriatic seismogenic zone. The main shock has caused cracking of the earth, especially in the region where the epicenter of the earthquake is located. The largest cracks are in the vicinity of the Erzen river estuary.<br>These cracks have widths ranging from few cms to 1m and extending from several hundred meters to 1 km. The depth of cracking in some cases reaches into 2 meters. Those cracks are numerous and often create parallel systems between them that follow the current river bed or traces of the old river beds (paleoalvei).<br>Liquefaction phenomena have been observed extensively in the area between the villages of Juba and Hamallaj. In this area, there have been observed outflows of pressure water associated with sand and clays. The height of the water has often reached up to 1 meter around the water wells. The phenomenon of liquefaction in these areas has been associated with soil cracks of several cms wide and several tens of meters long.<br>Based on the neotectonic mapping and the focal mechanism of the mainshock, strike 219°, dip 40°, rake -90°, it is considered that the seismotectonic source that generated thisearthquake is related to NW-SE longitudinal tectonic of the Adriatic Sea. Based on the focal plane solutions provided by the IGEWE website, the mainshock was generated by the activation of an NW-SE striking thrust fault with the compression axes in the NE-SW direction.</p><p>Sea Adriatic neotectonic extend from Dalmatic coast to Ionian coast is an ancient tectonic, a reverse fault thrust, thus activated during the Quaternary geologic period to the present day, occasionally with strong earthquakes. The seismic movement has also caused a 10 cm elevation of the terrain in the epicenter of the earthquake, which has been accompanied by a coastline retreat in this area (Hamallaj beach).<br>The 21 September and 26 November 2019 earthquake sequences, as well as the 1926 seismic event that took place in the Durresi region, exhibit a rough NW−SE-trending structure, which is an active seismotectonic zone in western Albania, therefore constituting a threat for nearby urban areas.</p>

scholarly journals MARJANBULAK EARTHQUAKE on MAY 25, 2013 with КР=14.1, МS=5.2, I0=7 (Djizakh province, Uzbekistan)

2019 ◽  
pp. 409-420
Author(s):  
M. Usmanova ◽  
A. Djuraev ◽  
M. Shermatov ◽  
A. Frolova ◽  
A. Sattarova
Keyword(s):  
Field Equation ◽  
Epicentral Zone ◽  
Instrumental Data ◽  
Isoseismal Map ◽  
Macroseismic Field ◽  
Observation Area ◽  
Geological Conditions ◽  
Engineer Geological ◽  
Macroseismic Survey

The instrumental data and the results of the macroseismic survey of the Marjanbulak earthquake MwMOS=6.2 with an intensity of 8 on the MSK-64 scale, which occurred in Uzbekistan, are presented. The isoseismal map is given. Correspondence between the intensity of the earthquake manifestation and the regional macroseismic field equation is shown. Geological and geophysical, engineer-geological conditions in the epicentral zone are described. The seismicity of the observation area is reviewed.

THE EMPIRICAL GREEN’S FUNCTION TECHNIQUE MODIFICATION FOR ACCELEROGRAM SYNTHESIS IN LOWSEISMICITY REGIONS

2018 ◽  
Vol 12 (5-6) ◽  
pp. 72-80
Author(s):  
A. A. Krylov
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Main Shock ◽  
Amplitude Spectrum ◽  
Strong Motion ◽  
Function Technique ◽  
Focal Region ◽  
Empirical Green’S Function ◽  
Epicentral Zone ◽  
Empirical Green's Function

In the absence of strong motion records at the future construction sites, different theoretical and semi-empirical approaches are used to estimate the initial seismic vibrations of the soil. If there are records of weak earthquakes on the site and the parameters of the fault that generates the calculated earthquake are known, then the empirical Green’s function can be used. Initially, the empirical Green’s function method in the formulation of Irikura was applied for main shock record modelling using its aftershocks under the following conditions: the magnitude of the weak event is only 1–2 units smaller than the magnitude of the main shock; the focus of the weak event is localized in the focal region of a strong event, hearth, and it should be the same for both events. However, short-termed local instrumental seismological investigation, especially on seafloor, results usually with weak microearthquakes recordings. The magnitude of the observed micro-earthquakes is much lower than of the modeling event (more than 2). To test whether the method of the empirical Green’s function can be applied under these conditions, the accelerograms of the main shock of the earthquake in L'Aquila (6.04.09) with a magnitude Mw = 6.3 were modelled. The microearthquake with ML = 3,3 (21.05.2011) and unknown origin mechanism located in mainshock’s epicentral zone was used as the empirical Green’s function. It was concluded that the empirical Green’s function is to be preprocessed. The complex Fourier spectrum smoothing by moving average was suggested. After the smoothing the inverses Fourier transform results with new Green’s function. Thus, not only the amplitude spectrum is smoothed out, but also the phase spectrum. After such preliminary processing, the spectra of the calculated accelerograms and recorded correspond to each other much better. The modelling demonstrate good results within frequency range 0,1–10 Hz, considered usually for engineering seismological studies.

LASER FLUOROSENSOR DEMONSTRATION FLIGHTS AROUND THE SOUTHERN COAST OF NEWFOUNDLAND

2005 ◽  
Vol 2005 (1) ◽  
pp. 1001-1005 ◽  
Author(s):  
Carl E. Brown ◽  
Mervin F. Fingas ◽  
Richard Marois
Keyword(s):  
Remote Sensing ◽  
North Atlantic ◽  
Real Life ◽  
Weather Conditions ◽  
Night Vision ◽  
Laser Fluorescence ◽  
Late Winter ◽  
Southern Coast ◽  
Oil Platforms ◽  
The North

ABSTRACT Several oil spill remote sensing flights were conducted by Environment Canada off the Southern coast of Newfoundland, Canada in late February, early March 2004. These flights were undertaken to demonstrate the capabilities of the Scanning Laser Environmental Airborne Fluorosensor (SLEAF) in real-life situations in the North Atlantic and Newfoundland coastal regions in late winter weather conditions. Geo-referenced infrared, ultraviolet, color video and digital still imagery was collected along with the laser fluorosensor data. Brief testing of a Generation III night vision camera was also conducted. Flights were conducted in the shipping lanes around the Newfoundland coast, out to the Hibernia and Terra Nova oil platforms and over known oil seep areas. Details of the analysis of laser fluorescence data collected during these flights will be presented along with a summary of the remote sensing flights.

scholarly journals Blue whales off the Southern coast of Sri Lanka during the Southwest Monsoon Season

2020 ◽  
Vol 21 (1) ◽  
pp. 1-7
Author(s):  
Grace Russell ◽  
Marcus Bridge ◽  
Maja Nimak-Wood
Keyword(s):  
Sri Lanka ◽  
Monsoon Season ◽  
Weather Conditions ◽  
Southwest Monsoon ◽  
Lower Latitude ◽  
Northeast Monsoon ◽  
Southern Coast ◽  
Northern India ◽  
Blue Whales ◽  
Southwest Monsoon Season

Observations of 37 individual blue whales (Balaenoptera musculus) were recorded off the southern coast of Sri Lanka during the Southwest Monsoon Season (SWM). Sightings were made during a scientific geophysical survey campaign conducted in July and August 2017. Whilst blue whales are regularly recorded on the continental slope of southern Sri Lanka during the Northeast Monsoon Season (NEM) (December - March) and during the two inter-monsoonal periods (March - April and September - October), limited data is available for the SWM (May - September) mostly due to unfavourable weather conditions and very little survey effort. In the northern hemisphere blue whales undertake seasonal migrations from higher latitude feeding grounds to lower latitude breeding and wintering areas. However it has been suggested that a population of blue whales in the Northern India Ocean (NIO) remains in lower latitudes year round taking advantage of the rich upwelling areas off Somalia, southwest Arabia and western Sri Lanka. Data from this study nevertheless support a theory that a certain number of individuals remain off the southern coast off Sri Lanka during the SWM, suggesting that the productivity in this region is sufficient to support their year-round presence. This study therefore fills a knowledge gap regarding the presence and movement of blue whales in the NIO highlighting the importance of data obtained from platforms of opportunity.

scholarly journals INVESTIGATION OF THE RELATIONSHIP BETWEEN IONOSPHERIC TEC ANOMALY VARIATIONS AND FAULT TYPES BEFORE THE EARTHQUAKES

2017 ◽  
Vol IV-4/W4 ◽  
pp. 383-388 ◽  
Author(s):  
M. Ulukavak ◽  
M. Yalçınkaya
Keyword(s):  
Total Electron Content ◽  
Space Weather ◽  
Environmental Changes ◽  
Weather Conditions ◽  
Earthquake Precursor ◽  
Strike Slip ◽  
Time Of Arrival ◽  
Electron Content ◽  
Total Electron ◽  
Fault Type

Earthquakes are natural phenomena that shake the earth and cause many damage. Since the time of arrival of the earthquakes cannot be determined directly, some signs before the earthquake should be examined and interpreted by examining the environmental changes. One of the methods used for this is monitoring the ionospheric total electron content (TEC) changes in total electron content unit (TECU). GPS satellites have begun to be used as a means of monitoring ionospheric TEC anomalies before earthquakes since they began to be used as sensors around the world. In this study, three fault type (normal, thrust and strike-slip faulting) of 28 earthquakes with a magnitude greater than 7 (Mw) and the percentage changes of TEC anomalies before the earthquakes were investigated. The ionospheric TEC anomalies before the earthquake were calculated according to the 15-day running median statistical analysis method. Different solar and geomagnetic indices have been investigated to determine the active space weather conditions and quiet days before and after the earthquake. The TEC anomalies were determined during the quiet days before the earthquake by comparing the ionospheric anomalies that occurred before the earthquake after the determination of quiet days with the indices of the space weather conditions. The results show that there is a relationship between fault type and the earthquake precursor percentage changes and were determined as 47.6 % TECU for regions where normal faulting, 50.4 % TECU for regions where thrust faulting, and 44.2 % TECU for regions where strike-slip faulting occurred, respectively.

scholarly journals Intensity and isoseismal map of 25th November 2007 Delhi earthquake

MAUSAM ◽  
2021 ◽  
Vol 62 (3) ◽  
pp. 417-424
Author(s):  
RAJESH PRAKASH ◽  
R.K. SINGH ◽  
A.K. SHUKLA ◽  
D. SINGH ◽  
B.S. RANA ◽  
...  
Keyword(s):  
Focal Depth ◽  
Analysis Tool ◽  
Stress Release ◽  
Isoseismal Map ◽  
Intensity Field ◽  
Statistical Analysis Tool ◽  
The Mean ◽  
Local Populace ◽  
Earthquake Effects ◽  
Macroseismic Survey

An earthquake of magnitude ML: 4.3 occurred on 25th November 2007 (2312 UTC) in Delhi with hypocenter at 28.56° N / 77.08° E and focal depth 33.1 km. The epicenter was at about 21 km SW of Delhi University. It was widely felt in and around Delhi and created panic among the local populace. A macroseismic survey was conducted in about ten days starting from 27th November, 2007 at 89 locations covering an area of about 1500 sq. km in Delhi and its neighborhood through a questionnaire. The results of the macroseismic survey allowed establishment of spatial distribution of the earthquake effects in the form of isoseismal map generated using geo-statistical analysis tool of ArcGIS 9.1. The isoseismal map shows that most parts of Delhi region experienced an intensity of V on MMI scale, except on northern most region of Delhi where intensity was found IV. The mean isoseismal radii for the zones V, IV, III and II are 29.13, 57.78, 83.63 and 100.75 km, respectively. The orientation of elongated epicentral track of intensity field shows that the stress release was pronounced along Delhi-Sargodha ridge and earthquake was attributed to activities of this ridge.

Mechanism of the main shock and the aftershock study of the Tabas-e-Golshan (Iran) earthquake of September 16, 1978: A preliminary report

1979 ◽  
Vol 69 (6) ◽  
pp. 1851-1859
Author(s):  
M. Berberian ◽  
I. Asudeh ◽  
R. G. Bilham ◽  
C. H. Scholz ◽  
C. Soufleris
Keyword(s):  
Focal Mechanism ◽  
Preliminary Report ◽  
Main Shock ◽  
Rupture Process ◽  
Rupture Zone ◽  
Local Network ◽  
Depth Range ◽  
Aftershock Activity ◽  
Surface Ruptures

abstract Aftershocks of the Tabas-e-Golshan earthquake (Ms = 7.7) of September 16, 1978 were recorded with a local network of portable seismometers. The main shock produced a discontinuous series of surface ruptures extending 85 km NNW and dipping ENE beneath the Shotori Range. The largest aftershocks located thus far are not concentrated in the hypocentral region of the main shock nor near the ends of the rupture zone but appear to be concentrated down-dip from gaps in the surface ruptures. This suggests that these features may extend to depth and act as barrier zones in the rupture process. The 65 km long zone of aftershock activity dips 40°ENE from the surface break, which agrees with the focal mechanism for the main shock in indicating thrusting on a NNW-striking, ENE-dipping fault. The aftershocks range in depth from 2 to 24 km with greatest concentration in the depth range 5 to 10 km.

Advances in earthquake-swarms monitoring networks WEBNET and REYKJANET

2020 ◽  
Author(s):  
Jakub Klicpera ◽  
Jana Doubravová ◽  
Josef Horálek
Keyword(s):  
Main Shock ◽  
Plate Boundary ◽  
Earthquake Swarms ◽  
Monitoring Networks ◽  
Epicentral Zone ◽  
Epicentral Area ◽  
The North ◽  
Short Period ◽  
West Bohemia ◽  
Reykjanes Peninsula

<p>The IG CAS in cooperation with IRSM CAS operates two local seismic networks deployed to monitor the seismic swarms in West Bohemia/Vogtland, Czechia and Reykjanes Peninsula, Iceland. </p><p>WEBNET monitors the region of West Bohemia since 1991 developing from 4 short period stations to 24 broadband stations today. The seismoactive region West Bohemia/Vogtland lies in the border area between Czechia and Germany in the western part of Bohemian Massif. It is an intra-continental area with persistent swarm-like seismicity but rarely also main-shock after-shock sequences may occur. </p><p>REYKJANET local seismic network is situated in Reykjanes Peninsula on Southwest Iceland. The area is an onshore part of the mid-Atlantic plate boundary between the North America and Eurasia Plates. The seismic activity of Reykjanes peninsula is represented by typical main-shock after-shock sequences as well as earthquake swarms. The REYKJANET network was built in 2013 and it consists of 15 stations placed around the epicentral area.</p><p>Both networks have been substantially upgraded during the last years. In case of REYKJANET the replacement of old sensors and digitizers with new ones made the operation easier and ready for near future plan to stream the waveform files in real time. WEBNET network which was long years divided into two subnets – on-line permanent stations and off-line autonomous stations, was recently homogenized by eco-powering and 4G LTE data connecting of the off-line stations. Additonally, the micro network HORNET was deployed within the WEBNET epicentral zone to monitor Horka water dam.</p><p>Data from both above mentioned networks are automatically searched for seismic events by the neural-network-based detector designed by Doubravová et al. (2016, 2019) providing event list with completeness magnitude Mc=0 for REYKJANET and Mc=-0.5 for WEBNET. The main difference of sensitivity is given by different noise levels of the two networks.</p>

scholarly journals Deep Diving with the Use of a Crabe Rebreather

2015 ◽  
Vol 51 (2) ◽  
pp. 11-24
Author(s):  
Ryszard Kłos
Keyword(s):  
Mathematical Model ◽  
Weather Conditions ◽  
Depth Range ◽  
Deep Diving

Abstract The article provides the results of 31 experimental dives carried out within the depth range of H ∈ [60; 80] mH2O. A combined mathematical model for ventilation and decompression was proposed with the possibility of an emergency omission of the last station at 3 mH2O and decompression completion at 6 mH2O in the event of a deterioration in weather conditions.

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