Heat flow near major strike-slip faults in California

Seventeen heat-flow measurements were made in crystalline rock near the San Andreas, San Jacinto, and Garlock faults, California, in regions representative of several levels of seismic activity. Data from these measurements, together with other heat-flow determinations in California and offshore along the continental borderland, do not clearly demonstrate the existence of a heat-flow anomaly in the vicinity of these major faults, although regularities in the data are present. The mean value of the seventeen determinations is 1.65 μcal/cm^2/sec, ±0.28 s.d. It is concluded that any or all of the following are the case: (a) the amount of energy converted to heat near a fault is no larger than that appearing as seismic waves; (b) the presently inferred rates of slip on the faults studied have been going on for only the last few million years or less; (c) the high density of fault systems in central and southern California contributes to a regionally high heat flow but prevents the resolution of energy from any single member; (d) the frictional heat generation varies from place to place along the faults. In the region between Lake Hughes and San Bernardino, now seismically inactive, but in the zone of rupture from the ∼8-magnitude Fort Tejon earthquake, six measurements show no correlation with distance from the San Andreas fault. Near the San Jacinto fault in the Peninsular Ranges, a region characterized by frequent intermediate- and low-magnitude earthquakes, determinations at 1 and 4 km from the fault are the same; they are 20% higher than a measurement 13 km to the west but are not appreciably different from a probable regional average 25 km to the east in the Imperial Valley. Near Hollister, where the San Andreas fault is creeping at a rate of several centimeters per year, a measurement 3 km west of the fault gives a value similar to those found elsewhere along the fault, yet significantly higher than values to the east on the western flank of the Sierra Nevada. Finally, measurements across the historically inactive Garlock fault exhibit high fluxes near the fault in comparison with a determination 8 km to the north, but these measurements are only slightly higher than values characteristic of the Mojave block to the south

Results from a 1500 m deep, three-level downhole seismometer array: Site response, low Q values, and f_(max)

A three-level downhole array is being operated in a 1500-m-deep borehole within the seismically active Newport-Inglewood fault zone, Los Angeles basin. The array consists of three three-component 4.5 Hz seismometers deployed at the surface, and at 420 and 1500 m depth. An M = 2.8 earthquake that occurred 0.9 km away from the array at a depth of 5.3 km on 31 July 1986 generated rays traveling almost vertically up the downhole array. The P- and S-wave pulse shapes show increasing pulse rise time with decreasing depth, and the initial pulse slope is less steep at the surface than at 1500 m. The average value of t_s/t_p between 1500 and 420 m depth is 1.7 and between 420 and 0 m is 3.4. A near-surface site response results in amplification on the P wave by a factor of four and S waves by a factor of nine. These data indicate a near-surface Q_α of 44 ± 13 for rays traveling almost vertically. In the case of S waves, most of the high frequency content of the waveform beyond ∼ 10 Hz observed at 1500 m depth is lost through attenuation before the waveform reaches 420 m depth. The average Q_β is 25 ± 10 between 1500 and 420 m depth and 108 ± 36 between 420 and 0 m depth. The spectra of the S waves observed at 420 and 0 m of the downward reflected S phases may overestimate Q_β, because they are limited to a narrow band between 5 and 10 Hz and affected by the near-surface amplification. A Q_c of 160 ± 30 at 6 Hz was determined from the decay rate of the coda waves at all three depths. The corner frequency as determined from displacement spectra may be higher (f_c ∼ 10 Hz) at 1500 m depth than at (f_c ∼ 7 Hz) 420 and 0 m depth. Similarly, f_(max) significantly decreases as the waveforms travel toward the earth's surface, indicating that f_(max) is affected by near-surface attenuation. Beyond f_c, the average slopes of the spectra falloff of P-wave spectra is ∼f^(−2) at 1500 m depth and ∼ f^(−3) at the surface

Grids of Stellar Models and Frequencies with CLES + LOSC

We present a grid of stellar models, obtained with the CLES evolution code, following the specification of ESTA-Task1, and the corresponfing seismic properties, computed with the LOSC code. We provide a complete description of the corresponding files that will be available on the ESTA web-pages.Comment: 8 pages, accepted for publication in Astrophys. Space Sci. (CoRoT/ESTA Volume

A model for charged second class currents

Choosing a model for the second class axial current composed of an s-wave vector current pseudoscalar meson pair to fix commutation relations, and using vector dominance (B-meson) techniques to calculate, we use recent experimental results to estimate the coupling strength of the second class current. Remarkably, within experimental errors we find that this coupling strength is the same as for the first class current, with the most natural normalization of the second class current. We comment on B-production and [Delta] production by neutrinos.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/21653/1/0000037.pd

Impact parameter study of high energy elastic scattering

The imaginary part of the proton-proton elastic scattering amplitude, as measured at the ISR, is examined in impact parameter. The transformed amplitude has two important properties. First, it is very accurately Gaussian in the impact parameter from the center to two fm with very little flattening near the center. Flattening would be expected from eikonalization. Secondly, there is a tail beyong two fm with a much flatter slope. This tail in impact parameter is equivalent to the break of d[sigma]/dt at t [approximate] -0.15 GeV.We discuss the physical origin of the tail. It cannot reasonably be diffraction dissociation, since diffraction should be large where absorption is large. We suggest that the tail is due to dissociation which must be distinguished from its diffractive part, and make a physical model which gives the tail and describes d[sigma]/dt very well. This model predicts the Deck model part of the diffraction inelastic cross section.We discuss the interpretation of elastic scattering in terms of s-channel unitarity rather than a t-channel exchange or the structure of a single hadron.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22392/1/0000841.pd