Applied to unmigrated data, the Common-Reflection-Surface (CRS) method is able to produce high-quality stacked sections, as well as useful traveltime parameters for a number of imaging and inversion purposes. One difficulty of the CRS method is the treatment of diffractions, especially when located close to reflections, and also triplications. In these regions, the CRS parameters obtained by co...

S U M M A R Y We present a significant addition to the data set of traveltimes of seismic PKP waves that sample the Earth’s lowermost mantle and core along the Earth’s rotation axis. Recorded at permanent Global Seismic Network (GSN) and temporary SSCUA deployment broadband seismographic stations in Antarctica, the new data improve the previously poor and biased coverage that underlies the seis...

S U M M A R Y We report on more than 100 earthquake waveform doublets in five subduction zones, including an earthquake nest in Bucaramanga, Colombia. Each doublet is presumed to be a pair of earthquakes that repeat at essentially the same location. These doublets are important for studying earthquake physics, as well as temporal changes of the inner core. Particularly, our observation from one...

Time-lapse geophysical measurements and seismic imaging methods in particular are powerful techniques for monitoring changes in reservoir properties. Traditional time-lapse processing methods treat each dataset as an independent unit and estimate changes in reservoir state through differencing these separate inversions. We present a general least-squares approach to jointly inverting time-varyi...

S U M M A R Y We present a resolution study of the velocity structure beneath Iceland as constrained by teleseismic traveltime tomography using data from the HOTSPOT seismic network. This temporary PASSCAL network and the tomographic technique that was used to generate the ICEMAN velocity models are typical of regional seismic studies. Therefore, this study also provides a basis for understandi...

The Interferometric Traveltime Tomography (ITT) method was previously shown to be both effective and stable in eliminating either shotor receiver-static errors using synthetic and field data example. In this report, we apply the ”closure phase” theorem to traveltime tomography and test its effectiveness in eliminating both the shotand receiver-static errors simultaneously with synthetic crosswe...