Ground deformation related to slip and afterslip of the 29 December 2020 Mw 6.4 Petrijna earthquake (Croatia) imaged by InSAR

2021 ◽  
Author(s):  
Athanassios Ganas ◽  
Sotiris Valkaniotis ◽  
Panagiotis Elias ◽  
Varvara Tsironi ◽  
Ilektra Karasante ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Moment Tensor ◽  
The South ◽  
Seismogenic Fault ◽  
Fault Surface ◽  
Seismic Fault ◽  
Vertical Fault ◽  
Horizontal Ground Motion ◽  
Dip Angle ◽  
The Right

<p>On December 29, 2020, at 11:19 UTC, a strong (M6.4), shallow earthquake occurred in the central region of Croatia. The epicentre was located near the town of Petrinja, about 40 km to the south of the capital, Zagreb. Here we present a preliminary analysis of the geodetic data (differential InSAR & GNSS) and preliminary estimates of the slip that occurred on the fault during the earthquake and subsequent aftershocks. We picked InSAR data to invert for the seismic fault assuming linear rheology and Okada-type dislocation (rectangular) source with non-uniform slip. The interferograms show an asymmetric, four‐lobed pattern, centered on a NW‐SE oriented discontinuity that is in agreement with the right-lateral plane of the moment tensor solutions for the mainshock. We found that the Petrijna earthquake ruptured a segment of a strike-slip fault zone that is shorter (8 km) than average and with larger slip (~ 3 m). All parameters of the seismic fault are well constrained by InSAR modeling due to the full azimuthal coverage with both ascending and descending data of good quality. The fit to the fringes is better with a steep dip angle (76°) than with a purely vertical fault. The upper edge of the modeled fault is at a depth of ~1 km, this means that the slip drop from 3 to 0 m in the uppermost kilometer and our geodetic analysis cannot assess whether the fault reached the surface in some sections of the fault, however should this be the case, we expect ruptures at the surface in the range of 0.1 to 0 m for consistency with our model and the structure of the fringes pattern. In particular, preliminary modelling results with distributed fault-slip show that the slip reached a peak of more than 2.5 m at a depth of about 2 km. We also found that, differently from what reported in the European database of seismogenic sources (EDSF), the seismic fault dips westward instead of eastward. Additionally, the 2020 rupture and the InSAR mapped trace do not match the EDSF composite seismogenic fault surface trace. Kinematic analysis of GNSS waveforms at station BJEL (about 70-km east of the epicentre) revealed that horizontal ground motion reached 7-cm (peak-to-peak). The InSAR data revealed a 7 km of right-lateral afterslip on the NW-edge of the rupture, and 5 km to the south of the main fault rupture. In particular, the afterslip data on the NW edge of the rupture document the curved shape of the post-seismic deformation, that highlights the non-planarity of faults in nature and possibly indicating the existence of a ramp structure connecting to the neighboring segment towards north.</p>

Failure Analysis Of Buried Gas Pipelines Crossing Seismic Faults

2020 ◽  
Vol 3 (2) ◽  
pp. 781-790
Author(s):  
M. Rizwan Akram ◽  
Ali Yesilyurt ◽  
A.Can. Zulfikar ◽  
F. Göktepe
Keyword(s):  
Ground Deformation ◽  
Warning System ◽  
Strike Slip ◽  
Gas Pipelines ◽  
Steel Pipes ◽  
Seismic Fault ◽  
Fault Parameters ◽  
Dip Angle ◽  
Permanent Ground Deformation ◽  
Recent Earthquakes

Research on buried gas pipelines (BGPs) has taken an important consideration due to their failures in recent earthquakes. In permanent ground deformation (PGD) hazards, seismic faults are considered as one of the major causes of BGPs failure due to accumulation of impermissible tensile strains. In current research, four steel pipes such as X-42, X-52, X-60, and X-70 grades crossing through strike-slip, normal and reverse seismic faults have been investigated. Firstly, failure of BGPs due to change in soil-pipe parameters have been analyzed. Later, effects of seismic fault parameters such as change in dip angle and angle between pipe and fault plane are evaluated. Additionally, effects due to changing pipe class levels are also examined. The results of current study reveal that BGPs can resist until earthquake moment magnitude of 7.0 but fails above this limit under the assumed geotechnical properties of current study. In addition, strike-slip fault can trigger early damage in BGPs than normal and reverse faults. In the last stage, an early warning system is proposed based on the current procedure. 

scholarly journals Characteristics of Secondary-Ruptured Faults in The Aso Caldera Triggered by The 2016 Mw 7.0 Kumamoto Earthquake

2020 ◽  
Author(s):  
Yo Fukushima ◽  
Daisuke Ishimura
Keyword(s):  
Scaling Law ◽  
Fault Slip ◽  
Sediment Layer ◽  
Seismogenic Fault ◽  
Kumamoto Earthquake ◽  
Synthetic Aperture Radar Interferometry ◽  
Vertical Fault ◽  
Aso Caldera ◽  
The Difference ◽  
The Right

Abstract The 16 April 2016 Mw 7.0 Kumamoto earthquake caused prominent fault displacements and crustal deformation, not only around the main rupture faults but also around numerous secondary-ruptured faults. The physics and characteristics of such secondary faulting have not yet been studied in detail. We investigated a set of two secondary faults that appeared at the timing of the Mw 7.0 quake in the Aso Caldera by mainly using synthetic aperture radar interferometry and fault slip modeling. The two faults were found to be associated with surface slip of several centimeters or more, in the oblique sense of right-lateral and vertical. Fault slip inversions found that the slip was dominantly in normal sense with smaller contribution from the right-lateral component. The deeper limit of the slips was estimated to be around 1.3¥,km, which may coincide with the boundary between the superficial sediment layer and the basement rock. The shallowness of the slip and the difference in the dip angles of the main secondary fault and the Mw 7.0 seismogenic fault suggest separation of the two fault systems, although the fault strike and sense of motions were similar. The amount of slip on the two secondary faults was larger than that expected from the scaling law derived from seismogenic faults, which may indicate the difference in the physics of seismogenic and secondary faultings.

scholarly journals Ground Deformation and Seismic Fault Model of the M6.4 Durres (Albania) Nov. 26, 2019 Earthquake, Based on GNSS/INSAR Observations

Geosciences ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 210 ◽  
Author(s):  
Athanassios Ganas ◽  
Panagiotis Elias ◽  
Pierre Briole ◽  
Flavio Cannavo ◽  
Sotirios Valkaniotis ◽  
...  
Keyword(s):  
Seismic Moment ◽  
Ground Deformation ◽  
Satellite System ◽  
Recurrence Time ◽  
Moment Tensors ◽  
Robust Solution ◽  
Fault Surface ◽  
Seismic Fault ◽  
Shortening Rate ◽  
Global Navigation Satellite

We identify the source of the Mw = 6.4 earthquake that rocked north-central Albania on November 26, 2019 02:54 UTC. We use synthetic aperture radar interferograms tied to the time series of coordinates of two permanent Global Navigation Satellite System (GNSS) stations (DUR2 and TIR2). We model the source by inverting the displacement data. Assuming in our model a half-space elastic medium and uniform slip along a rectangular fault surface, we invert the 104 picked measurements on a couple of ascending and descending interferograms to calculate the parameters of the fault. All inversions made with different input parameters converge towards a stable and robust solution with root mean square (r.m.s.) residual of 5.4 mm, thus ~1/5 of a fringe. They reveal that the earthquake occurred deep in the crust on a low-angle fault (23°) dipping towards east with a centroid at 16.5 km depth. The best-fitting length and width of the fault are 22 and 13 km, and the reverse slip, 0.55 m. The seismic moment deduced from our model agrees with those of the published seismic moment tensors. This geometry is compatible with a blind thrust fault that may root on the main basal thrust, i.e., along the thrust front that separates Adria–Apulia from Eurasia. It is notable that there is a 123 ns yr−1 active shortening of the crust between the GNSS stations DUR2-TIR2 (equivalent to a shortening rate of 3.6 mm yr−1), and roughly in the east–west direction. Given this amount of strain the recurrence time of M6+ earthquakes along this fault should be of the order of 150 years.

scholarly journals Co-Seismic and Postseismic Fault Models of the 2018 Mw 6.4 Hualien Earthquake Occurred in the Junction of Collision and Subduction Boundaries Offshore Eastern Taiwan

2018 ◽  
Vol 10 (9) ◽  
pp. 1372 ◽  
Author(s):  
Ying-Hui Yang ◽  
Jyr-Ching Hu ◽  
Hsin Tung ◽  
Min-Chien Tsai ◽  
Qiang Chen ◽  
...  
Keyword(s):  
Rake Angle ◽  
The South ◽  
Seismogenic Fault ◽  
The West ◽  
Sar Images ◽  
The North ◽  
Coulomb Failure ◽  
Main Fault ◽  
Dip Angle ◽  
Postseismic Slip

The ascending and descending InSAR deformations derived from ALOS-2 and Sentinel-1 satellite SAR images and GPS displacements are used to estimate the fault model of the 2018 Mw 6.4 Hualien earthquake. The sinistral strike-slip fault dipping to the west with a high dip angle of 89.4° and a rake angle of 201.7° is considered as the seismogenic fault of this event. This seismogenic fault also triggered the ruptures of the Milun fault, which dips to the east with a dip angle of ~72°, and an unknown west-dipping fault with a dip angle of 85.2°. Two predicted faulting models indicate that the InSAR deformation fields include more postseismic slip than those of the GPS data. The north segment of the Milun fault and west-dipping fault have been triggered by the rupture of the seismogenic fault, but the postseismic slip occurred only in the south segment of the Milun fault. The InSAR-derived co-seismic and postseismic faulting model suggests that the significant slip concentrates at depths of 2.4–15.0 km of the main fault, 0.0–14.0 km of the Milun fault. Only minor slip is detected on the west-dipping fault. The maximum fault slip of ca. 2.1 m is located at the depth of ca. 2.4 km under the Meilun Tableland. The Coulomb failure stress (CFS) change calculated by the co-seismic and postseismic faulting model shows that there is a significant CFS increase in the east of the south segment of the Milun fault, but few of the aftershocks occur in this area, which indicates a high risk of future seismic hazard.

KINERJA APARATUR SIPIL NEGARA STUDI KASUS KANTOR KECAMATAN MOROTAI SELATAN KABUPATEN PULAU MOROTAI

2019 ◽  
Vol 4 (1) ◽  
pp. 8
Author(s):  
Ibnu Kanaha
Keyword(s):  
Work Performance ◽  
Working Hours ◽  
The South ◽  
Job Descriptions ◽  
Improve Performance ◽  
District Office ◽  
Use Of Time ◽  
State Apparatus ◽  
The Right ◽  
Depth Interviews

The purpose of this study was to determine the performance of employees (ASN) in the South Morotai District office. The form of this research is descriptive qualitative, with data collection techniques through observation and in-depth interviews with the subdistrict head, subdistrict head secretary, employees, and the community. This study concluded that employees at the South Morotai District Office were not disciplined in terms of time, both when they entered the office and after working hours. Employees are not able to make the best use of time to do productive work to improve performance. employees generally do not know and understand their respective fields of duty. The concept of the right man in the right place is not applied in the placement of employees. Performance evaluation of employees at the South Morotai District Office is difficult because of unclear job descriptions and division of tasks for the state apparatus. This causes the work performance is not measurable both in quality and quantity..

The Villa Item and a Bride's Ordeal

1929 ◽  
Vol 19 (1) ◽  
pp. 67-87 ◽  
Author(s):  
Jocelyn Toynbee
Keyword(s):  
The South ◽  
Important Paper ◽  
The North ◽  
Dwelling House ◽  
South Wall ◽  
The Subject ◽  
The One ◽  
The Individual ◽  
North Wall ◽  
The Right

The paintings in the triclinium of the Villa Item, a dwelling-house excavated in 1909 outside the Porta Ercolanese at Pompeii, have not only often been published and discussed by foreign scholars, but they have also formed the subject of an important paper in this Journal. The artistic qualities of the paintings have been ably set forth: it has been established beyond all doubt that the subject they depict is some form of Dionysiac initiation: and, of the detailed interpretations of the first seven of the individual scenes, those originally put forward by de Petra and accepted, modified or developed by Mrs. Tillyard appear, so far as they go, to be unquestionably on the right lines. A fresh study of the Villa Item frescoes would seem, however, to be justified by the fact that the majority of previous writers have confined their attention almost entirely to the first seven scenes—the three to the east of the entrance on the north wall (fig. 3), the three on the east wall and the one to the east of the window on the south wall, to which the last figure on the east wall, the winged figure with the whip, undoubtedly belongs.

§ XI.—Hellenistic Mycenae

1923 ◽  
Vol 25 ◽  
pp. 408-428
Author(s):  
C. A. Boethius
Keyword(s):  
Common Type ◽  
The Other ◽  
The South ◽  
Left Hand ◽  
The Right

Among the ruins of the Hellenistic buildings at the south end of the Great Ramp, in the fourth or southern chamber (Pl. I. 34), three fragments of a stele (now in the Nauplia Museum) were found. The stele is of a simple and common type, and is made of the same white limestone as the other Mycenaean stele found by Tsountas, which it closely resembles even in its weathering. Except for the top left-hand corner and a gap on the right side the whole stele is preserved. It is ·969 m. in height, ·41–·436 m. in breadth (·41 m. at the ninth line of the inscription) and ·11–·125 m. thick. At the top there is a plain frieze, ·065 m. high : ·02 m. below the frieze begins an inscription which fills twenty lines and ends ·50 m. above the bottom of the stele. The letters are ·008–·01 m. high. The space between the lines is ·009–·011 m. The surface of the stone is very much worn, and it was consequently difficult to make out the letters and their accurate forms. The sketch (Fig. 93) shows the arrangement of the text.

A Middle Assyrian Hoard from Khirbet Karhasan, Iraq

Iraq ◽  
1992 ◽  
Vol 54 ◽  
pp. 157-182 ◽  
Author(s):  
David Tucker ◽  
David S. Reese
Keyword(s):  
Western Slope ◽  
The South ◽  
North West ◽  
The Rich ◽  
The Right

Khirbet Karhasan was excavated by the British Archaeological Expedition to Iraq, as part of the Saddam Dam Salvage Project. The excavations brought to light a hoard of Middle Assyrian faience ornaments, which formed a coherent assemblage. Collections of similar ornaments are known from Assur and Nimrud where they have been variously interpreted as decorating the rich garments for a god, a divine image, and even the walls of temples. In the absence of any other persuasive view a hypothesis is advanced based on the evidence of archaeological context, iconographic associations and a viable reconstruction, that the ornaments are equally adaptable to the decoration of ceremonial horse-harness.The tell of Khirbet Karhasan is situated on the right bank of the Tigris approximately 75 km north-west of Mosul. The site on the edge of a prominent terrace overlooks a broad floodplain. In 1986, prior to the flooding of the site, the Tigris channel was 3 km north of the tell. The tell was sheltered by low hills which formed the western slope of the valley some 500 m to the south of the site. The hills rose some 40 m above the tell to approximately 50 m above the floodplain.

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