Uplift and subsidence associated with the great Aceh‐Andaman earthquake of 2004

Meltzner, A. J.; Sieh, Kerry; Abrams, Michael J.; Agnew, Duncan Carr; Hudnut, K. W.; Avouac, Jean Philippe; Natawidjaja, D. H.

doi:10.1029/2005jb003891

Cited by 216 publications

(183 citation statements)

References 16 publications

Supporting

Mentioning

169

Contrasting

Unclassified

Order By: Relevance

“…Observations of emerged coral microatols, both from in situ observations and satellite imagery [14], show uplift and subsidence of coral reefs surrounding the Andaman and Nicobar islands and the Indonesian archipelago, as do SAR images of coastal areas [27]. However, these observations lack the spatial coverage needed to constrain models of sea level change.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Ocean contribution to co-seismic crustal deformation and geoid anomalies: Application to the 2004 December 26 Sumatra–Andaman earthquake

Broerse

Vermeersen

Riva

et al. 2011

Earth and Planetary Science Letters

View full text Add to dashboard Cite

Large earthquakes do not only heavily deform the crust in the vicinity of the fault, they also change the gravity field of the area affected by the earthquake due to mass redistribution in the upper layers of the Earth. Besides that, for sub-oceanic earthquakes deformation of the ocean floor causes relative sea level changes and mass redistribution of water that have again a significant effect on the gravity field. To model these deformations, sea level changes and gravity field perturbations self-consistently we use an adapted version of the sea level equation (SLE) that has been used for glacial isostatic adjustment studies. The sea level equation, next to our normal mode model for seismic solid earth modelling, allows us to compute a gravitationally self-consistent solution for the co-seismic relative sea level, surface deformation and geoid height changes. We apply our geographically detailed models to the case of the 2004 December 26 Sumatra-Andaman earthquake. Recent studies that have modelled the ocean mass effect on co-seismic gravity change for this specific earthquake show model results that indicate a broad negative change in geoid height around the fault due to ocean water redistribution [5], [13]. Our model results for the ocean contribution to geoid height differ from these studies in the sense that we find a pattern similar to the elongated dipole pattern of the solid earth model outputs for gravity and vertical deformation, together with a relatively small broad negative geoid height change. We explain the relation between outcomes for geoid height, relative sea level and vertical deformation of the ocean floor and we confront our model results with a least squares estimation of the co-seismic discontinuity in GRACE-derived gravity field time series. We show that taking into account the contribution of ocean water redistribution to the co-seismic geoid height change next to a compressible solid earth model is essential to explain the predominant negative co-seismic geoid anomalies from the GRACE gravity field solutions. Besides, we introduce a detailed approach to modelling an earthquake in a normal mode model that better approximates realistic continuous slip on the fault plane than models that do not distribute slip with depth. To demonstrate the importance of the slip distribution we show the differences in outcomes for modelled geoid height and vertical deformation.

show abstract

Section: Introductionmentioning

confidence: 99%

“…All gravity data is downward continued to a radius of 6371 km. The data we include in our analysis starts at (14) where a to g are constants, ω is 161/365, the 161-day S2 tidal alias phase, t the time in years and t eq the time of the earthquake.…”

Section: Gracementioning

confidence: 99%

Ocean contribution to co-seismic crustal deformation and geoid anomalies: Application to the 2004 December 26 Sumatra–Andaman earthquake

Broerse

Vermeersen

Riva

et al. 2011

Earth and Planetary Science Letters

View full text Add to dashboard Cite

show abstract

“…Namely, when the bathymetry changes during an earthquake-up to a few metres of uplift and subsidence have been measured for recent megathrust earthquakes (Meltzner et al 2006;Farías et al 2010)-the height of the water column is adjusted, resulting in a redistribution of water. Uplift of the seafloor results in a local water mass removal and subsidence leads to a local water accumulation, see the scheme of Fig.…”

mentioning

confidence: 99%

Ocean contribution to seismic gravity changes: the sea level equation for seismic perturbations revisited

Broerse¹,

Riva²,

Vermeersen³

2014

Geophysical Journal International

View full text Add to dashboard Cite

S U M M A R YDuring megathrust earthquakes, great ruptures are accompanied by large scale mass redistribution inside the solid Earth and by ocean mass redistribution due to bathymetry changes. These large scale mass displacements can be detected using the monthly gravity maps of the GRACE satellite mission. In recent years it has become increasingly common to use the long wavelength changes in the Earth's gravity field observed by GRACE to infer seismic source properties for large megathrust earthquakes. An important advantage of space gravimetry is that it is independent from the availability of land for its measurements. This is relevant for observation of megathrust earthquakes, which occur mostly offshore, such as the M w ∼ 9 2004 Sumatra-Andaman, 2010 Maule (Chile) and 2011 Tohoku-Oki (Japan) events. In Broerse et al., we examined the effect of the presence of an ocean above the rupture on long wavelength gravity changes and showed it to be of the first order.Here we revisit the implementation of an ocean layer through the sea level equation and compare the results with approximated methods that have been used in the literature. One of the simplifications usually lies in the assumption of a globally uniform ocean layer. We show that especially in the case of the 2010 Maule earthquake, due to the closeness of the South American continent, the uniform ocean assumption is not valid and causes errors up to 57 per cent for modelled peak geoid height changes (expressed at a spherical harmonic truncation degree of 40). In addition, we show that when a large amount of slip occurs close to the trench, horizontal motions of the ocean floor play a mayor role in the ocean contribution to gravity changes. Using a slip model of the 2011 Tohoku-Oki earthquake that places the majority of slip close to the surface, the peak value in geoid height change increases by 50 per cent due to horizontal ocean floor motion. Furthermore, we test the influence of the maximum spherical harmonic degree at which the sea level equation is performed for sea level changes occurring along coastlines, which shows to be important for relative sea level changes occurring along the shore. Finally, we demonstrate that ocean floor loading, self-gravitation of water and conservation of water mass are of second order importance for coseismic gravity changes.When GRACE observations are used to determine earthquake parameters such as seismic moment or source depth, the uniform ocean layer method introduces large biases, depending on the location of the rupture with respect to the continent. The same holds for interpreting shallow slip when horizontal motions are not properly accounted for in the ocean contribution. In both cases the depth at which slip occurs will be underestimated.

show abstract

“…The fifth data set is the 3-D co-seismic displacements derived from survey mode GPS data in Sumatra by Subarya et al (2006). The last data set is vertical displacements obtained from coral reef measurements and pivot lines of satellite images reported also by Subarya et al (2006) and Meltzner et al (2006). Although this sort of data have large uncertainty (tens of centimeter), it can constrain the fault model for its near distance.…”

Section: Datamentioning

confidence: 99%

Co-seismic fault geometry and slip distribution of the 26 December 2004, giant Sumatra–Andaman earthquake constrained by GPS, coral reef, and remote sensing data

et al. 2015

View full text Add to dashboard Cite

We analyze co-seismic displacement field of the 26 December 2004, giant Sumatra-Andaman earthquake derived from Global Position System observations, geological vertical measurement of coral head, and pivot line observed through remote sensing. Using the co-seismic displacement field and AK135 spherical layered Earth model, we invert co-seismic slip distribution along the seismic fault. We also search the best fault geometry model to fit the observed data. Assuming that the dip angle linearly increases in downward direction, the postfit residual variation of the inversed geometry model with dip angles linearly changing along fault strike are plotted. The geometry model with local minimum misfits is the one with dip angle linearly increasing along strike from 4.3 o in top southernmost patch to 4.5 o in top northernmost path and dip angle linearly increased. By using the fault shape and geodetic co-seismic data, we estimate the slip distribution on the curved fault. Our result shows that the earthquake ruptured *200-km width down to a depth of about 60 km. 0.5-12.5 m of thrust slip is resolved with the largest slip centered around the central section of the rupture zone 78N-108N in latitude. The estimated seismic moment is 8.2 9 10 22 N m, which is larger than estimation from the centroid moment magnitude (4.0 9 10 22 N m), and smaller than estimation from normal-mode oscillation data modeling (1.0 9 10 23 N m).

show abstract

Uplift and subsidence associated with the great Aceh‐Andaman earthquake of 2004

Cited by 216 publications

References 16 publications

Ocean contribution to co-seismic crustal deformation and geoid anomalies: Application to the 2004 December 26 Sumatra–Andaman earthquake

Ocean contribution to co-seismic crustal deformation and geoid anomalies: Application to the 2004 December 26 Sumatra–Andaman earthquake

Ocean contribution to seismic gravity changes: the sea level equation for seismic perturbations revisited

Co-seismic fault geometry and slip distribution of the 26 December 2004, giant Sumatra–Andaman earthquake constrained by GPS, coral reef, and remote sensing data

Contact Info

Product

Resources

About