Annual Meeting - SCEC.org

Poster Abstracts
The Whittier fault offsets major streams in the foothills of the Puente Hills, and it presents a hazard from a strike-slip
earthquake. However, the fault has reverse separation, north-side-up, and its footwall is uplifted by folding imaged by oilwell
data supported by shallow instrumental seismicity from Yang and Hauksson (2011). The Whittier fault masks an anticline
deformed on an underlying blind reverse fault that poses a separate hazard.
Similarly, the earthquake hazard from the Newport-Inglewood fault has been limited previously to right-lateral strike slip,
similar to the 1933 Long Beach earthquake. However, Gilluly and Grant (1949) documented coseismic uplift immediately east
of the fault in 1933, suggesting a reverse-fault subevent northwest of the strike-slip mainshock near Newport Beach. In
addition, Hauksson (1987) documented reverse-fault-plane solutions, particularly in the northern half of the onshore fault
trace. In addition, the discontinuous strike-slip fault traces in this part of the Newport-Inglewood zone extend along the crest
of the broad Central Uplift anticline, bounded on the northeast by the active Compton-Los Alamitos reverse fault. We suggest
that this deformation, like the Whittier fault system, involves strain partitioning.
The Palos Verdes fault has a right-lateral strike-slip rate of 2.7-3.8 mm/yr in Los Angeles Harbor. However, marine terraces in
the Palos Verdes Hills show reverse-oblique slip along the fault of 3.0-3.7 mm/yr. Brankman and Shaw (2009) identified a
southwest-dipping reverse-oblique-slip fault with a long-term oblique-slip rate of 4 mm/yr.
The next earthquake on one of these faults, then, could be a strike-slip fault like the 1933 Long Beach earthquake, a reverse-slip
earthquake like the aftershocks of the 2010 Léogâne earthquake, or an oblique-reverse-slip event like the 1989 Loma Prieta
earthquake. Each of these possibilities should be considered in the Community Fault Model.
THE FUTURE OF VIRTUAL CALIFORNIA SIMULATIONS (B-110)
M.B. Yikilmaz, J.B. Rundle, D.L. Turcotte, E.M. Heien, M.K. Sachs, and L.H. Kellogg
The Virtual California (VC) simulation code produces a long term synthetic catalog of earthquakes on major faults in
California. The input is the slip rates and the recurrence intervals on the faults. At the present time the simulations produce
complexity and statistical distribution of earthquakes on major faults. Straight forward future studies can:
1) Produce fault to fault correlations of activity (cross-correlations)
2) Produce maps of shaking for California based on the long term synthetic catalogs available from VC.
3) It is desirable to include the extension of displacements beneath the seismogenic zone. This is particularly important for
fault to fault jumps.
4) Currently, fault jumps are inhibited by the stiff elastic region between faults. It may be necessary to introduce damage zone
to enhance transfer of stress.
CHANGE IN STATISTICS FROM A DIMENSIONAL TRANSITION: MEASURING B = 1.5 FOR LARGE
EARTHQUAKES (B-083)
M.R. Yoder, J.R. Holliday, D.L. Turcotte, and J.B. Rundle
We identify two distinct scaling regimes in the frequency-magnitude distribution of global earthquakes. Specifically, we
measure the scaling exponent b = 1.0 for “small” earthquakes with 5.5 < m < 7.6 and b = 1.5 for “large” earthquakes with 7.6 <
m < 9.0. This transition at mb = 7.6, can be explained by geometric constraints on the rupture. In conjunction with supporting
literature, this corroborates theories in favor of fully self-similar and magnitude independent earthquake physics. We also
show that the scaling behavior and abrupt transition between the scaling regimes implies that earthquake ruptures have
compact shapes and smooth rupture-fronts.
PRODUCTS AND SERVICES AVAILABLE FROM THE SOUTHERN CALIFORNIA EARTHQUAKE DATA
CENTER (SCEDC) AND THE SOUTHERN CALIFORNIA SEISMIC NETWORK (SCSN) (B-066)
E. Yu, A. Bhaskaran, S. Chen, M.J. Ihrig, F. Chowdhury, S. Meisenhelter, K. Hutton, D. Given, E. Hauksson, and R. Clayton
Currently the SCEDC archives continuous and triggered data from nearly 8400 data channels from 425 SCSN recorded
stations, processing and archiving an average of 6.4 TB of continuous waveforms and 12,000 earthquakes each year. The
SCEDC provides public access to these earthquake parametric and waveform data through its website www.data.scec.org and
through client applications such as STP and DHI. This poster will describe the most significant developments at the SCEDC
during 2011.
2011 SCEC Annual Meeting | 257