scholarly journals On the Integrated Surface Uplift for Dip‐Slip Faults

2019 ◽  
Vol 109 (6) ◽  
pp. 2738-2740 ◽  
Author(s):  
Paul Segall ◽  
Elías Rafn Heimisson
Keyword(s):  
Hanging Wall ◽  
Central Italy ◽  
Vertical Displacement ◽  
Elastic Half Space ◽  
Synthetic Aperture ◽  
Interferometric Synthetic Aperture Radar ◽  
Central Italy Earthquake ◽  
Surface Uplift ◽  
Volume Collapse ◽  
Volume Estimates

Abstract Interferometric Synthetic Aperture Radar observations often provide maps of vertical displacement that can be integrated to estimate an uplift volume. Relating this measure to source processes requires a model of the deformation. Bignami et al. (2019) argue that the negative uplift volume associated with the 2016 Amatrice–Norcia, central Italy, earthquake sequence requires a coseismic volume collapse of the hanging wall. Using results for dip‐slip dislocations in an elastic half‐space we show that Vuplift=(P/4)(1−2ν)sin(2δ), in which P is the seismic potency, ν is the Poisson’s ratio, and δ is the fault dip, consistent with an earlier result of Ward (1986). For reasonable estimates of net potency for the 2016 Amatrice–Norcia sequence, this simple formula yields uplift volume estimates close to that observed. We conclude that the data are completely consistent with elastic dislocation theory and do not require a volume collapse at depth.

scholarly journals Identification and characterization of alpine subglacial lakes using interferometric synthetic aperture radar (InSAR): Brady Glacier, Alaska, USA

2010 ◽  
Vol 56 (199) ◽  
pp. 861-870 ◽  
Author(s):  
Denny M. Capps ◽  
Bernhard Rabus ◽  
John J. Clague ◽  
Daniel H. Shugar
Keyword(s):  
Synthetic Aperture Radar ◽  
Vertical Displacement ◽  
Synthetic Aperture ◽  
Interferometric Synthetic Aperture Radar ◽  
Glacier Surface ◽  
Discharge Rates ◽  
Outburst Floods ◽  
Glacier Dynamics ◽  
Subglacial Lakes ◽  
Aperture Radar

AbstractThe temporary storage and subsequent release of water at glacial margins can cause severe flooding in downstream areas and substantially impact glacier dynamics. Alpine subglacial lakes may not be identified until they become subaerially exposed or release a jokulhlaup. We use interferometric synthetic aperture radar (InSAR) to identify and characterize three dynamic alpine subglacial lakes of Brady Glacier, Alaska, USA. We quantify changes in vertical displacement of the glacier surface and lake volumes from September 1995 through March 1996 using European Remote-sensing Satellite-1/-2 (ERS- 1/-2) tandem data. In the autumn, subsidence ranged from 4 to 26cmd-1 and the volume of water discharged ranged from 22 000 ± 2000 to 243 000 ± 14 000m3d-1. Subsidence and discharge rates declined significantly during the winter and continued at a lesser rate through March. Application of this technique may allow researchers to locate alpine subglacial lakes years or decades before they begin to release hazardous outburst floods and substantially impact glacier dynamics.

scholarly journals DETECTING DEFORMATION DUE TO THE 2018 MERAPI VOLCANO ERUPTION USING INTERFEROMETRIC SYNTHETIC APERTURE RADAR (INSAR) FROM SENTINEL-1 TOPS

2019 ◽  
Vol 16 (1) ◽  
pp. 45
Author(s):  
Suwarsono Suwarsono ◽  
Indah Prasasti ◽  
Jalu Tejo Nugroho ◽  
Jansen Sitorus ◽  
Rahmat Arief ◽  
...  
Keyword(s):  
Synthetic Aperture Radar ◽  
Volcanic Activity ◽  
Vertical Displacement ◽  
Synthetic Aperture ◽  
Optical Data ◽  
Landsat 8 ◽  
Interferometric Synthetic Aperture Radar ◽  
Merapi Volcano ◽  
The Impact ◽  
Aperture Radar

This paper describes the application of Sentinel-1 TOPS (Terrain Observation with Progressive Scans), the latest generation of SAR satellite imagery, to detect displacement of the Merapi volcano due to the May–June 2018 eruption. Deformation was detected by measuring the vertical displacement of the surface topography around the eruption centre. The Interferometric Synthetic Aperture Radar (InSAR) technique was used to measure the vertical displacement. Furthermore, several Landsat-8 Thermal Infra Red Sensor (TIRS) imageries were used to confirm that the displacement was generated by the volcanic eruption. The increasing temperature of the crater was the main parameter derived using the Landsat-8 TIRS, in order to determine the increase in volcanic activity. To understand this phenomenon, we used Landsat-8 TIRS acquisition dates before, during and after the eruption. The results show that the eruption in the May–June 2018 period led to a small negative vertical displacement. This vertical displacement occurred in the peak of volcano range from -0.260 to -0.063 m. The crater, centre of eruption and upper slope of the volcano experienced negative vertical displacement. The results of the analysis from Landsat-8 TIRS in the form of an increase in temperature during the 2018 eruption confirmed that the displacement detected by Sentinel-1 TOPS SAR was due to the impact of volcanic activity. Based on the results of this analysis, it can be seen that the integration of SAR and thermal optical data can be very useful in understanding whether deformation is certain to have been caused by volcanic activity.

scholarly journals Strong Ground Motion Characteristics from 2016 Central Italy Earthquake Sequence

2018 ◽  
Vol 34 (4) ◽  
pp. 1611-1637 ◽  
Author(s):  
Paolo Zimmaro ◽  
Giuseppe Scasserra ◽  
Jonathan P. Stewart ◽  
Tadahiro Kishida ◽  
Giuseppe Tropeano ◽  
...  
Keyword(s):  
Earthquake Engineering ◽  
Hanging Wall ◽  
Central Italy ◽  
Normal Fault ◽  
Earthquake Sequence ◽  
Rupture Directivity ◽  
Global Models ◽  
Engineering Research ◽  
Central Italy Earthquake ◽  
Anelastic Attenuation

The Central Italy earthquake sequence has, to date, generated three mainshocks: M6.1 24 August, M5.9 26 October, and M6.5 30 October 2016. These events, along with aftershocks, were well recorded by Italian networks, and are among the normal fault earthquakes with the highest number of recordings globally. We process records for six events using procedures developed during the latest Next Generation Attenuation (NGA-West2) project, coordinated by the Pacific Earthquake Engineering Research Center (PEER). Many recording sites lacked V S30 assignments, which we provide using measured shear wave velocity profiles where available and a local geology proxy otherwise. Stations at close distance, including near the hanging wall, exhibit fling step in some cases but no obvious rupture directivity. The data exhibit fast anelastic attenuation at large distances (>100 km), as predicted by recent Italy-adjusted global models, but not by Italy-specific models. We partition residuals from Italy-adjusted global models, finding negative event terms at short periods (weaker than average shaking). We apply Kriging of within-event peak acceleration and velocity residuals using a global semi-variogram model to estimate the spatial distribution of peak accelerations and velocities, which are generally most intense southwest of Mt. Vettore.

scholarly journals Coseismic fault-slip distribution of the 2019 Ridgecrest Mw6.4 and Mw7.1 earthquakes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yang Gao ◽  
HuRong Duan ◽  
YongZhi Zhang ◽  
JiaYing Chen ◽  
HeTing Jian ◽  
...  
Keyword(s):  
Strike Slip ◽  
Fault Slip ◽  
Slip Distribution ◽  
Synthetic Aperture ◽  
Seismic Events ◽  
Interferometric Synthetic Aperture Radar ◽  
The Past ◽  
Dextral Strike Slip Fault ◽  
Fault Slip Distribution ◽  
Dextral Strike Slip

AbstractThe 2019 Ridgecrest, California seismic sequence, including an Mw6.4 foreshock and Mw7.1 mainshock, represent the largest regional seismic events within the past 20 years. To obtain accurate coseismic fault-slip distribution, we used precise positioning data of small earthquakes from January 2019 to October 2020 to determine the dip parameters of the eight fault geometry, and used the Interferometric Synthetic Aperture Radar (InSAR) data processed by Xu et al. (Seismol Res Lett 91(4):1979–1985, 2020) at UCSD to constrain inversion of the fault-slip distribution of both earthquakes. The results showed that all faults were sinistral strike-slips with minor dip-slip components, exception for dextral strike-slip fault F2. Fault-slip mainly occurred at depths of 0–12 km, with a maximum slip of 3.0 m. The F1 fault contained two slip peaks located at 2 km of fault S4 and 6 km of fault S5 depth, the latter being located directly above the Mw7.1hypocenter. Two slip peaks with maximum slip of 1.5 m located 8 and 20 km from the SW endpoint of the F2 fault were also identified, and the latter corresponds to the Mw6.4 earthquake. We also analyzed the influence of different inversion parameters on the fault slip distribution, and found that the slip momentum smoothing condition was more suitable for the inversion of the earthquakes slip distribution than the stress-drop smoothing condition.

Sign in / Sign up

Export Citation Format

Share Document