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Laske, G, Phipps Morgan J, Orcutt JA.  2007.  The Hawaiian SWELL pilot experiment; evidence for lithosphere rejuvenation from ocean bottom surface wave data. GSA Special Paper. 430:209-233.   10.1130/2007.2430(11)   Abstract

During the roughly year-long Seismic Wave Exploration in the Lower Lithosphere (SWELL) pilot experiment in 1997/1998, eight ocean bottom instruments deployed to the southwest of the Hawaiian Islands recorded teleseismic Rayleigh waves with periods between 15 and 70 s. Such data are capable of resolving structural variations in the oceanic lithosphere and upper asthenosphere and therefore help understand the mechanism that supports the Hawaiian Swell relief. The pilot experiment was a technical as well as a scientific feasibility study and consisted of a hexagonal array of Scripps Low-Cost Hardware for Earth Applications and Physical Oceanography (L-CHEAPO) instruments using differential pressure sensors. The analysis of eighty-four earthquakes provided numerous high-precision phase velocity curves over an un-precedentedly wide period range. We find a rather uniform (unaltered) lid at the top of the lithosphere that is underlain by a strongly heterogeneous lower lithosphere and upper asthenosphere. Strong slow anomalies appear within ∼300 km of the island chain and indicate that the lithosphere has most likely been altered by the same process that causes the Hawaiian volcanism. The anomalies increase with depth and reach well into the asthenosphere, suggesting a sublithospheric dynamic source for the swell relief. The imaged velocity variations are consistent with thermal rejuvenation, but our array does not appear to have covered the melt-generating region of the Hawaiian hotspot.

Priestley, K, Orcutt JA, Brune JN.  1980.  Higher-Mode Surface-Waves and Structure of the Great-Basin of Nevada and Western Utah. Journal of Geophysical Research. 85:7166-7174.   10.1029/JB085iB12p07166   AbstractWebsite

Observed seismograms and dispersion data for crust and mantle higher mode surface waves in the Great Basin are compared with theoretical seismograms and dispersion curves computed for the Great Basin model of Priestley and Brune [1978]. This structure was originally derived from fundamental mode surface wave and refraction data. Phases identified as Sa [T∼13 s] are observed to have a phase velocity of 4.50±0.03 km s−1. Crustal second Rayleigh mode (first shear mode) waves have predominant periods varying from about 5 s on some paths to about 8 s on others. The observed excitation and phase velocity of the Sa phase are in agreement with theoretical seismograms and computed phase velocities for a modified Great Basin model. The agreement provides added support, in an unexpected way, for the existence of a mantle lid of velocity about 4.5 km s−1 in the Great Basin. The crustal higher mode group velocity observations, i.e., the predominant periods of the second Rayleigh mode along various paths, reflect variations in crustal thickness within the Great Basin. Crustal thicknesses of approximately 25 km are indicated for some paths in northwestern Nevada and southeastern Oregon, whereas crustal thicknesses of greater than 35 km are indicated for east central Nevada. The crustal thickness of 35 km in the Great Basin model is probably most appropriate for the central part of the Great Basin.

Berger, J, Orcutt J, Vernon F.  2005.  HiSeasNet: Providing Internet to the UNOLS fleet. Sea Technology. 46:17-20. AbstractWebsite
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Van Avendonk, HJA, Harding AJ, Orcuttt JA, Holbrook WS.  2001.  Hybrid shortest path and ray bending method for traveltime and raypath calculations. Geophysics. 66:648-653.   10.1190/1.1444955   AbstractWebsite

The shortest path method (SPM) is a robust ray-tracing technique that is particularly useful in 3-D tomographic studies because the method is well suited for a strongly heterogeneous seismic velocity structure. We test the accuracy of its traveltime calculations with a seismic velocity structure for which the nearly exact solution is easily found by conventional ray shooting. The errors in the 3-D SPM solution are strongly dependent on the choice of search directions in the "forward star," and these errors appear to accumulate with traveled distance. We investigate whether these traveltime errors can be removed most efficiently by an SPM calculation on a finer grid or by additional ray bending. Testing the hybrid scheme on a realistic ray-tracing example, we find that in an efficient mix ray banding and SPM account for roughly equal amounts of computation time. The hybrid method proves to be an order of magnitude more efficient than SPM without ray bending in our example. We advocate the hybrid ray-tracing technique, which offers an efficient approach to find raypaths and traveltimes for large seismic refraction studies with high accuracy.