scholarly journals Seismic intensity assignments for the 2008 Andravida (NW Peloponnese, Greece) strike-slip event (June 8, Mw=6.4) based on the application of the Environmental Seismic Intensity scale (ESI 2007) and the European Macroseismic scale (EMS-98)

2014 ◽  
Vol 56 (6) ◽  
Author(s):  
Spyridon D. Mavroulis ◽  
Ioannis G. Fountoulis ◽  
Emmanuel N. Skourtsos ◽  
Efthymis L. Lekkas ◽  
Ioannis D. Papanikolaou
Keyword(s):  
Structural Damage ◽  
Surface Deformation ◽  
Active Tectonics ◽  
Geological Structure ◽  
Seismic Intensity ◽  
Strike Slip ◽  
Masonry Buildings ◽  
Small Surface ◽  
Geotechnical Characteristics ◽  
Slip Event

On June 8, 2008, a strike-slip earthquake (Mw=6.4) was generated NE of the Andravida town (NW Peloponnese, western Greece) due to the activation of the previously unknown western Achaia strike-slip fault zone (WAFZ). Extensive structural damage and earthquake environmental effects (EEE) were induced in the NW Peloponnese, offering the opportunity to test and compare the ESI 2007 and the EMS-98 intensity scales in a moderate strike-slip event. No primary EEE were induced, while secondary EEE including seismic fractures, liquefaction phenomena, slope movements and hydrological anomalies were widely observed covering an area of about 800 km<sup>2</sup>. The lack of primary effects and the relatively small surface deformation with respect to the earthquake magnitude is due to the thick Gavrovo flysch layer in the affected area that isolated and absorbed the subsurface deformation from the surface. According to the application of the EMS-98 scale, damage to masonry buildings ranged from grade 3 to 5, while damage in most of R/C buildings ranged from grade 1 to 3. A maximum ESI 2007 intensity VIII-IX is recorded, while the maximum EMS-98 intensity is IX. For all the sites where intensity VIII has been recorded the ESI 2007 and the EMS-98 agree, but for others the ESI 2007 intensities values are lower by one or two degrees than the corresponding EMS-98 ones, as it is clearly concluded from the comparison of the produced isoseismals. An exception to this rule is the Valmi village, where considerable structural damage occurs (IX<sub>EMS-98</sub>) along with the lack of significant EEE (V<sub>ESI 2007</sub>). This variability between the ESI 2007 and the EMS-98 intensity values is predominantly attributed to the vulnerability of old masonry buildings constructed with no seismic resistance design. Correlation of all existing data shows that the geological structure, the active tectonics, and the geotechnical characteristics of the alpine and post-alpine formations along with the construction type of buildings were of decisive importance in the damage and the EEE distribution.

The role of the remarkable Seram-Kumawa strike-slip fault in the tectonic process of the northern Banda Arc system

2020 ◽  
Author(s):  
Xiaodong Yang ◽  
Satish C. Singh ◽  
Ian Deighton
Keyword(s):  
Subduction Zones ◽  
Surface Deformation ◽  
Active Tectonics ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
Benioff Zone ◽  
Accretionary Wedge ◽  
Geophysical Research ◽  
Fault Plane Solutions ◽  
Banda Arc

&lt;p&gt;&lt;span&gt;The Banda Arc system is sited in a junction of &lt;/span&gt;convergence between the Eurasian, Indo-Australian, Philippine and Pacific plates&lt;span&gt;. It &lt;/span&gt;has a remarkable 180&amp;#176; curve in the Benioff zone&lt;span&gt;. Two fundamental ideas have been invoked to explain this significant subduction-arc orientation change: (1) bent subduction zone around the Banda Sea (Hamilton, 1979; Spakman and Hall, 2010; Hall, 2012)&lt;/span&gt;, or (2) oppositely dipping subduction zones (Cardwell and Isacks, 1978; McCaffrey, 1989), b&lt;span&gt;ut no general agreement exists as to the cause of this curvature. However, a WNW-trending strike-slip fault, i.e. Seram-Kumawa fault, is observed at the north-eastern end of the Arc, cutting through the Seram accretionary wedge, prism and trench and seems to continue on the subducting plate (Hall et al., 2017). This fault is either inactive or locked temporarily at the present day, because there are very few strike-slip events along its trend while there are many thrust earthquakes on its north and northwest side. A few essential questions remain unanswered about this fault in relation to the evolution of the Banda Arc. For instance, what is the origin of this fault, what role does it play in the tectonic processes and large earthquakes along the Banda Arc. Could this fault eventually break-up the Banda Arc? What is its tectonic implication on the evolution of other highly curved subduction-arc systems? To address these questions, we will carry out a comprehensive investigation into active tectonics and seismicity occurrence along the northeast Banda Arc using high-resolution bathymetry, 2D marine seismic profiles and earthquake data. &lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Reference:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;span&gt;&lt;span&gt;Cardwell, R.K. and Isacks, B.L., 1978. Geometry of the subducted lithosphere beneath the Banda Sea in eastern Indonesia from seismicity and fault plane solutions. Journal of Geophysical Research: Solid Earth, 83(B6): 2825-2838.&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;span&gt;Hall, R., 2012. Late Jurassic&amp;#8211;Cenozoic reconstructions of the Indonesian region and the Indian Ocean. Tectonophysics, 570: 1-41.&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;span&gt;Hall, R., Patria, A., Adhitama, R., Pownall, J.M. and White, L.T., 2017. Seram, the Seram Trough, the Aru Trough, the Tanimbar Trough and the Weber Deep: A new look at major structures in the eastern Banda Arc.&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;span&gt;Hamilton, W.B., 1979. Tectonics of the Indonesian region. US Govt. Print. Off.&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;span&gt;McCaffrey, R., 1989. Seismological constraints and speculations on Banda Arc tectonics. Netherlands Journal of Sea Research, 24(2-3): 141-152.&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;span&gt;Spakman, W. and Hall, R., 2010. Surface deformation and slab&amp;#8211;mantle interaction during Banda arc subduction rollback. Nature Geoscience, 3(8): 562.&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

Active Tectonics and Paleoseismicity of the Eastern Issyk-Kul Basin (Kyrgyzstan, Tien Shan)

2021 ◽  
Vol 62 (03) ◽  
pp. 263-277
Author(s):  
A.M. Korzhenkov ◽  
E.V. Deev ◽  
I.V. Turova ◽  
S.V. Abdieva ◽  
S.S. Ivanov ◽  
...  
Keyword(s):  
Surface Deformation ◽  
Late Quaternary ◽  
Active Tectonics ◽  
Historical Earthquakes ◽  
Strike Slip ◽  
Tien Shan ◽  
Quaternary Sediments ◽  
The South ◽  
Large Earthquakes ◽  
Tectonic Movements

Abstract —The Malyi Orgochor, Orgochor, Birbash, Sukhoi Ridge, Ichketosma, and Tosma uplifts in the eastern Issyk-Kul basin are fault-related anticlinal folds composed of Neogene and Quaternary sediments involved in tectonic movements. The folds have asymmetric transversal profiles, with low-angle southern limbs and steep northern limbs cut by segments of the South Issyk-Kul and Karkara reverse faults reactivated in the late Quaternary. The location and geometry of the two faults, which both show reverse and left-lateral strike slip components, correspond to neotectonic propagation of deformation from the Terskey-Ala-Too Range over almost the whole eastern Issyk-Kul basin. Judging by primary and secondary coseismic surface deformation in the area, the South Issyk-Kul and Karkara faults repeatedly generated large earthquakes (M ≥ 7, I ≥ 9) in the Late Pleistocene and Holocene. According to trenching results, the historical earthquakes that occurred in the first and 10–11th centuries accommodated motions on the South Issyk-Kul fault. The new seismotectonic and paleoseismicity data from the eastern Issyk-Kul basin provide updates to its seismic potential.

Geomorphology, Geological Structure, Active Tectonics, and Basin Formation in the Aegean Sea

2021 ◽  
Author(s):  
D. Sakellariou ◽  
G. Rousakis ◽  
P. Drakopoulou ◽  
K. Tsampouraki-Kraounaki ◽  
I. Morfis ◽  
...  
Keyword(s):  
Active Tectonics ◽  
Aegean Sea ◽  
Geological Structure ◽  
Basin Formation

scholarly journals Application of the Environmental Seismic Intensity scale (ESI 2007) and the European Macroseismic Scale (EMS-98) to the Kalamata (SW Peloponnese, Greece) earthquake (Ms=6.2, September 13, 1986) and correlation with neotectonic structures and active faults

2014 ◽  
Vol 56 (6) ◽  
Author(s):  
Ioannis G. Fountoulis ◽  
Spyridon D. Mavroulis
Keyword(s):  
Structural Damage ◽  
Active Fault ◽  
Main Shock ◽  
Active Faults ◽  
Seismic Hazard Assessment ◽  
Seismic Intensity ◽  
Fault Zones ◽  
Earthquake Sequence ◽  
Ground Subsidence ◽  
Earthquake Scenario

On September 13, 1986, a shallow earthquake (Ms=6.2) struck the city of Kalamata and the surrounding areas (SW Peloponnese, Greece) resulting in 20 fatalities, over 300 injuries, extensive structural damage and many earthquake environmental effects (EEE). The main shock was followed by several aftershocks, the strongest of which occurred two days later (Ms=5.4). The EEE induced by the 1986 Kalamata earthquake sequence include ground subsidence, seismic faults, seismic fractures, rockfalls and hydrological anomalies. The maximum ESI 2007 intensity for the main shock has been evaluated as IX<sub>ESI 2007</sub>, strongly related to the active fault zones and the reactivated faults observed in the area as well as to the intense morphology of the activated Dimiova-Perivolakia graben, which is a 2nd order neotectonic structure located in the SE margin of the Kalamata-Kyparissia mega-graben and bounded by active fault zones. The major structural damage of the main shock was selective and limited to villages founded on the activated Dimiova-Perivolakia graben (IX<sub>EMS-98</sub>) and to the Kalamata city (IX<sub>EMS-98</sub>) and its eastern suburbs (IX<sub>EMS-98</sub>) located at the crossing of the prolongation of two major active fault zones of the affected area. On the contrary, damage of this size was not observed in the surrounding neotectonic structures, which were not activated during this earthquake sequence. It is concluded that both intensity scales fit in with the neotectonic regime of the area. The ESI 2007 scale complemented the EMS-98 seismic intensities and provided a completed picture of the strength and the effects of the September 13, 1986, Kalamata earthquake on the natural and the manmade environment. Moreover, it contributed to a better picture of the earthquake scenario and represents a useful and reliable tool for seismic hazard assessment.

scholarly journals Analisis Penurunan Muka Tanah dengan Small Baseline Subset Differential SAR Interferograms di Kota Bandar Lampung

2020 ◽  
Vol 5 (2) ◽  
pp. 30-43
Author(s):  
Bagas Setyadi ◽  
Rustadi Rustadi
Keyword(s):  
Land Subsidence ◽  
Structural Damage ◽  
Geological Structure ◽  
Tectonic Activity ◽  
Land Conversion ◽  
Consolidation Process ◽  
Lack Of Information ◽  
Geological Conditions ◽  
Deformation Speed ◽  
Industrial Mining

Bandar Lampung is one of the cities in Indonesia, which has a potential to land subsidence due to the extraction of ground water, mining, land conversion, and geological conditions. For that reason, carried out the study of land subsidence with SBAS technique, due to the very lack of information about the symptoms of land subsidence in Bandar Lampung. In this study, 15 SAR data in 2006 to 2011 used and then combined to produce 40 interferogram then inverted resulting in a time-series deformation and deformation speed average. Velocity precision obtained with SBAS technique is highly dependent on the type of land cover in the study area, but it is known that the average of land subsidence in Bandar Lampung is about 0.06 mm/year, which is considered quite stable due to the geological structure that does not allow for the occurrence of massive consolidation process. Several areas have indications of subsidence 5 mm/year are suspected to be caused by tectonic activity and human activity (industrial, mining, extraction of groundwater, and land conversion), which then has implications for structural damage to buildings, flooding in coastal areas, and landslides in hilly areas.

scholarly journals Slip‐rate on the Main Köpetdag (Kopeh Dagh) Strike‐slip fault, Turkmenistan, and the active tectonics of the South Caspian

Tectonics ◽  
2021 ◽  
Author(s):  
Richard Thomas Walker ◽  
Y. Bezmenov ◽  
G. Begenjev ◽  
S. Carolin ◽  
N. Dodds ◽  
...  
Keyword(s):  
Active Tectonics ◽  
Slip Rate ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
The South

Evidence of Fault Immaturity from Shallow Slip Deficit and Lack of Postseismic Deformation of the 2017 Mw 6.5 Jiuzhaigou Earthquake

2020 ◽  
Vol 110 (1) ◽  
pp. 154-165 ◽  
Author(s):  
Yuexin Li ◽  
Roland Bürgmann ◽  
Bin Zhao
Keyword(s):  
Wenchuan Earthquake ◽  
Fault Zone ◽  
Surface Deformation ◽  
Strike Slip ◽  
Stress Change ◽  
Depth Interval ◽  
Postseismic Deformation ◽  
Jiuzhaigou Earthquake ◽  
2008 Wenchuan Earthquake ◽  
Slip Deficit

ABSTRACT The Mw 6.5 Jiuzhaigou earthquake occurred on 8 August 2017 36 km west-southwest of Yongle, Sichuan, China. We use both ascending and descending Interferometric Synthetic Aperture Radar (InSAR) data from Sentinel-1 and coseismic offsets of four Global Positioning System sites to obtain the coseismic surface deformation field and invert for the fault geometry and slip distribution. Most slip of the left-lateral strike-slip earthquake occurred in the 3–10 km depth interval with a maximum slip of about 1 m and a large shallow slip deficit (SSD). An eight-month InSAR time-series analysis documents a lack of resolvable postseismic deformation, and inversions for the distribution of postseismic slip demonstrate the lack of shallow afterslip. We argue that the observations of a pronounced SSD and no early afterslip of the Jiuzhaigou earthquake are indicative of an immature fault and that all incipient young strike-slip faults likely feature a SSD. We would expect a complex rupture geometry with distributed coseismic failure in the uppermost part of the brittle crust during the fault-zone development. As faults mature, they straighten out, develop a localized fault-zone core, and the SSD diminishes. By calculating the static Coulomb stress change and nine-year viscoelastic stress change caused by the Wenchuan earthquake, we also show that the 2008 Wenchuan earthquake did not significantly affect the time of occurrence of the 2017 Jiuzhaigou earthquake.

scholarly journals A physics-based approach of deep interseismic creep for viscoelastic strike-slip earthquake cycle models

2019 ◽  
Vol 220 (1) ◽  
pp. 79-95
Author(s):  
Lucile Bruhat
Keyword(s):  
Surface Deformation ◽  
Slip Rate ◽  
Strike Slip ◽  
Dynamic Rupture ◽  
Crust And Upper Mantle ◽  
Slip Rates ◽  
Region I ◽  
Best Fitting ◽  
Time Invariant ◽  
Analytical Expressions

SUMMARY Most geodetic inversions of surface deformation rates consider the depth distribution of interseismic fault slip-rate to be time invariant. However, some numerical simulations show downdip penetration of dynamic rupture into regions with velocity-strengthening friction, with subsequent updip propagation of the locked-to-creeping transition. Recently, Bruhat and Segall developed a new method to characterize interseismic slip rates, that allows slip to penetrate up dip into the locked region. This simple model considered deep interseismic slip as a crack loaded at its downdip end, and provided analytical expressions for stress drop within the crack, slip and slip rate along the fault. This study extends this approach to strike-slip fault environments, and includes coupling of creep to viscoelastic flow in the lower crust and upper mantle. I use this model to investigate interseismic deformation rates along the Carrizo Plain section of the San Andreas fault. This study reviews possible models, elastic and viscoelastic, for fitting horizontal surface rates. Using this updated approach, I develop a physics-based solution for deep interseismic creep which accounts for possible slow vertical propagation, and investigate how it improves the fit of the horizontal deformation rates in the Carrizo Plain region. I found solutions for fitting the surface deformation rates that allow for reasonable estimates for earthquake rupture depth and coseismic displacement and improves the overall fit to the data. Best-fitting solutions present half-space relaxation time around 70 yr, and very low propagation speeds, less than a metre per year, suggesting a lack of creep propagation.

Comparison of macroseismic-intensity scales by considering empirical observations of structural seismic damage

2020 ◽  
pp. 875529302094417
Author(s):  
Siqi Li ◽  
Yongsheng Chen ◽  
Tianlai Yu
Keyword(s):  
Structural Damage ◽  
Damage Index ◽  
Seismic Damage ◽  
Seismic Intensity ◽  
Calculation Model ◽  
Macroseismic Intensity ◽  
Intensity Scale ◽  
Failure Characteristics ◽  
Damage Survey ◽  
Seismic Engineering

In practice, seismic intensity is evaluated in accordance with a macroseismic-intensity scale recognized in the field of seismic engineering globally. The application of different seismic-intensity scales to evaluate the seismic damage of a specific structure due to an earthquake yields diverse results. On this basis, this study compared a few extensively used macroseismic-intensity scales. The results can be used as a reference to develop an international intensity scale. According to empirical structural-damage survey data from the Wenchuan earthquake (Mw = 8.0) that occurred on 12 May 2008 in China, the European Macroseismic Scale (EMS)-98, Medvedev, Sponheuer, and Karnik (MSK)-81, and Chinese Seismic Intensity Scale (CSIS)-08 intensity scales were utilized to evaluate the resulting damage. This study carried out a vulnerability analysis of typical structures, established vulnerability seismic-damage matrices, and mapped out vulnerability curves under different intensities. Our objective is to demonstrate that the use of multiple intensity scales can lead to very different intensity levels. The differences in the damage of typical structures under different intensity levels were obtained from an evaluation using the three aforementioned intensity scales. As a result, a calculation model of the mean damage index is proposed herein. Ultimately, this article conducted an analysis on the failure characteristics of typical structures in an earthquake and provided effective measures to improve seismic performance for future reference.

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