Results 1 - 10
of
703
Implementation and testing of the method of splitting tsunami (MOST) model
- NOAA Technical Memorandum ERL PMEL-112, 11 pp UNIDATA
, 1997
"... Mention of a commercial company or product does not constitute an endorsement by NOAA/ERL. Use of information from this publication concerning proprietary products or the tests of such products for publicity or advertising purposes is not authorized. ..."
Abstract
-
Cited by 54 (9 self)
- Add to MetaCart
(Show Context)
Mention of a commercial company or product does not constitute an endorsement by NOAA/ERL. Use of information from this publication concerning proprietary products or the tests of such products for publicity or advertising purposes is not authorized.
Comparison between three-dimensional linear and nonlinear tsunami generation models, Theor. Comput. Fluid Dyn
"... The modeling of tsunami generation is an essential phase in understanding tsunamis. For tsunamis generated by underwater earthquakes, it involves the modeling of the sea bottom motion as well as the resulting motion of the water above it. A comparison between various models for three-dimensional wat ..."
Abstract
-
Cited by 34 (18 self)
- Add to MetaCart
(Show Context)
The modeling of tsunami generation is an essential phase in understanding tsunamis. For tsunamis generated by underwater earthquakes, it involves the modeling of the sea bottom motion as well as the resulting motion of the water above it. A comparison between various models for three-dimensional water motion, ranging from linear theory to fully nonlinear theory, is performed. It is found that for most events the linear theory is sufficient. However, in some cases, more sophisticated theories are needed. Moreover, it is shown that the passive approach in which the seafloor deformation is simply translated to the ocean surface is not always equivalent to the active approach in which the bottom motion is taken into account, even if the deformation is
Crustal deformation across and beyond the Los Angeles basin, from geodetic measurements
- J. geophys. Res
, 1996
"... Abstract. We combine 6 years of Global Positioning System (GPS) data with 20 years of trilateration data and a century of triangulation, taped distance, and astronomic azimuth measurements to derive 66 interseismic station velocities in the greater Los Angeles region. We interpolate the velocities t ..."
Abstract
-
Cited by 32 (1 self)
- Add to MetaCart
Abstract. We combine 6 years of Global Positioning System (GPS) data with 20 years of trilateration data and a century of triangulation, taped distance, and astronomic azimuth measurements to derive 66 interseismic station velocities in the greater Los Angeles region. We interpolate the velocities to construct a regional strain rate map beyond the Los Angeles basin. Our results generally agree with the model proposed by the Working Group on California Earthquake Probabilities in 1995. Important regional findings of this study are as follows: (1) There is a significant N-S convergence and E-W extension, about 0.22 and 0.17 •: 0.05 #strain/yr, respectively, for the two components, along the southern frontal fault system ofthe San Gabriel Mountains. (2) The crustal deformation around the Big Bend of the San Andreas fault (SAF) cannot be explained solely by wrench-style motion across the SAF. Remaining motion could be part of a NW-SE extension which is the response to NF•SW compression i the central Transverse Ranges region. Alternatively, it could be caused by left-lateral faulting on an oblique blind thrust beneath the San Gabriel Mountains. (3) Low strain rates axe found along the Elsinore fault and Newport-Inglewood fault. (4) North-south compression decreases from the Raymond Hill fault westward to the Santa Monica fault. There is little east-west extension along this fault system.
Source rupture process of the 2003 Tokachi-oki earthquake determined by joint inversion of teleseismic body wave and strong ground motion data, Earth Planets Space
, 2004
"... The spatio-temporal slip distribution of the 2003 Tokachi-oki, Japan, earthquake was estimated from teleseismic body wave and strong ground motion data. To perform stable inversion, we applied smoothing constraints to the slip distribution with respect to time and space, and determined the optimal w ..."
Abstract
-
Cited by 31 (1 self)
- Add to MetaCart
(Show Context)
The spatio-temporal slip distribution of the 2003 Tokachi-oki, Japan, earthquake was estimated from teleseismic body wave and strong ground motion data. To perform stable inversion, we applied smoothing constraints to the slip distribution with respect to time and space, and determined the optimal weights of constraints using an optimized Akaike’s Bayesian Information Criterion (ABIC). We found that the rupture propagates mainly along the dip direction, and the length of the rupture area is shorter than its width. The mean rise time in the shallow asperity is significantly longer than that in the deep asperity, which might be attributed to variable frictional properties or lower strength of the plate interface at shallower depths. The average rupture velocity of deep asperity extends to the shear-wave velocity. The derived source parameters are as follows: seismic moment Mo = 1.7×1021 Nm (Mw 8.0); source duration = 50 sec. We also estimated the shear stress change due to the mainshock on and around the major fault zone. It appears that many aftershocks on the plate boundary took place in and adjacent to the zones of stress increase due to the rupture of the mainshock.
2008), Heterogeneous coupling of the Sumatran megathrust constrained by geodetic and paleogeodetic measurements
- J. Geophys. Res
"... [1] Geodetic and paleogeodetic measurements of interseismic strain above the Sumatran portion of the Sunda subduction zone reveal a heterogeneous pattern of coupling. Annual banding in corals provides vertical rates of deformation spanning the last half of the 20th century, and repeated GPS surveys ..."
Abstract
-
Cited by 31 (5 self)
- Add to MetaCart
(Show Context)
[1] Geodetic and paleogeodetic measurements of interseismic strain above the Sumatran portion of the Sunda subduction zone reveal a heterogeneous pattern of coupling. Annual banding in corals provides vertical rates of deformation spanning the last half of the 20th century, and repeated GPS surveys between 1991 and 2001 and continuous measurements at GPS stations operated since 2002 provide horizontal velocities. Near the equator, the megathrust is locked over a narrow width of only a few tens of kilometers. In contrast, the locked fault zone is up to about 175 km wide in areas where great interplate earthquakes have occurred in the past. Formal inversion of the data reveals that these strongly coupled patches are roughly coincident with asperities that ruptured during these events. The correlation is most spectacular for rupture of the Mw 8.7 Nias-Simeulue earthquake of 2005, which released half of the moment deficit that had accumulated since its previous rupture in 1861, suggesting that this earthquake was overdue. Beneath the Mentawai islands, strong coupling is observed within the overlapping rupture areas of the great earthquakes of 1797 and 1833. The accumulated slip deficit since these events is slowly reaching
Detailed observations of California foreshock sequences: implications for the earthquake initiation process
, 1996
"... sequences: Implications for the earthquake ..."
Recalculated probability of M 7 earthquakes beneath the Sea of Marmara
, 2004
"... [1] New earthquake probability calculations are made for the Sea of Marmara region and the city of Istanbul, providing a revised forecast and an evaluation of time-dependent interaction techniques. Calculations incorporate newly obtained bathymetric images of the North Anatolian fault beneath the Se ..."
Abstract
-
Cited by 27 (3 self)
- Add to MetaCart
(Show Context)
[1] New earthquake probability calculations are made for the Sea of Marmara region and the city of Istanbul, providing a revised forecast and an evaluation of time-dependent interaction techniques. Calculations incorporate newly obtained bathymetric images of the North Anatolian fault beneath the Sea of Marmara [Le Pichon et al., 2001; Armijo et al., 2002]. Newly interpreted fault segmentation enables an improved regional A.D. 1500– 2000 earthquake catalog and interevent model, which form the basis for time-dependent probability estimates. Calculations presented here also employ detailed models of coseismic and postseismic slip associated with the 17 August 1999 M = 7.4 Izmit earthquake to investigate effects of stress transfer on seismic hazard. Probability changes caused by the 1999 shock depend on Marmara Sea fault-stressing rates, which are calculated with a new finite element model. The combined 2004–2034 regional Poisson probability of M 7 earthquakes is 38%, the regional time-dependent probability is 44 ± 18%, and incorporation of stress transfer raises it to 53 ± 18%. The most important effect of adding time dependence and stress transfer to the calculations is an increase in the 30 year probability of a M 7 earthquake affecting Istanbul. The 30 year Poisson
India and Sunda plates motion and deformation along their boundary in Myanmar determined by
, 2006
"... [1] Using a regional GPS data set including 190 stations in Asia, from Nepal to eastern Indonesia and spanning 11 years, we update the present-day relative motion between the Indian and Sundaland plates and discuss the deformation taking place between them in Myanmar. Revisiting measurements acquire ..."
Abstract
-
Cited by 26 (2 self)
- Add to MetaCart
(Show Context)
[1] Using a regional GPS data set including 190 stations in Asia, from Nepal to eastern Indonesia and spanning 11 years, we update the present-day relative motion between the Indian and Sundaland plates and discuss the deformation taking place between them in Myanmar. Revisiting measurements acquired on the Main Boundary Thrust in Nepal, it appears that points in southern Nepal exhibit negligible deformation with respect to mainland India. Including these points, using a longer time span than previous studies, and making an accurate geodetic mapping in the newest reference frame allows us to refine the present-day Indian motion. Our results confirm that the current motion of India is slower than predicted by the NUVEL-1A model, and in addition our India-Eurasia motion is significantly (5 mm/yr) slower than previous geodetic determinations. This new Indian motion, combined with a refined determination of the Sundaland motion, gives way to a relative India-Sunda angular velocity of 20.2N, 26.1E, 0.370/Myr in ITRF2000, predicting a relative motion of 35 mm/yr oriented N10 at the latitude of Myanmar. There, the Sagaing Fault accommodates only 18 mm/yr of right-lateral strike slip, only half of the shear component of motion. We present two models addressing how and where the
L.: 2002, Complex earthquake rupture and local tsunamis
- J. Geophys. Res. 107, ESE
"... [1] In contrast to far-field tsunami amplitudes that are fairly well predicted by the seismic moment of subduction zone earthquakes, there exists significant variation in the scaling of local tsunami amplitude with respect to seismic moment. From a global catalog of tsunami runup observations this v ..."
Abstract
-
Cited by 24 (8 self)
- Add to MetaCart
[1] In contrast to far-field tsunami amplitudes that are fairly well predicted by the seismic moment of subduction zone earthquakes, there exists significant variation in the scaling of local tsunami amplitude with respect to seismic moment. From a global catalog of tsunami runup observations this variability is greatest for the most frequently occurring tsunamigenic subduction zone earthquakes in the magnitude range of 7 < Mw < 8.5. Variability in local tsunami runup scaling can be ascribed to tsunami source parameters that are independent of seismic moment: variations in the water depth in the source region, the combination of higher slip and lower shear modulus at shallow depth, and rupture complexity in the form of heterogeneous slip distribution patterns. The focus of this study is on the effect that rupture complexity has on the local tsunami wave field. Awide range of slip distribution patterns are generated using a stochastic, self-affine source model that is consistent with the falloff of far-field seismic displacement spectra at high frequencies. The synthetic slip distributions generated by the stochastic source model are discretized and the vertical displacement fields from point source elastic dislocation expressions are superimposed to compute the coseismic vertical displacement field. For shallow subduction zone earthquakes it is demonstrated that self-affine irregularities of the slip distribution result in significant variations in
Interseismic coupling and asperity distribution along the kamchatka subduction zone
- Journal of Geophysical Research - Solid Earth
, 2005
"... zone ..."
(Show Context)
