544 D. Submarine Geology and Geophysics OLR (1988) 35 (6)

are described, and earthquake location uncertainty, magnitude smoothing and distance smoothing, and the parameters controlling smoothing are discussed. (hbf)

88:3412 Faure, Gunter (ed.), 1987. New developments and

applications in isotope geoscience. A selection of papers presented at an open session during the Sixth International Conference on Geochronol- ogy, Cosmochronology and Isotope Geology (ICOG IV), Cambridge, Great Britain, June 30 to July 4, 1986. Chem. Geol., 66(1-2):177pp; 17 papers.

Topics covered at the open session included new instrumentation and calibration, analytical tech- niques, and new applications and discoveries. Six of the selected papers deal with various aspects of the 4°mr/39Ar technique and dating standards and an- other four treat U-Pb geochronology. Other papers consider the Rb--Sr and K-Ca isotope systematics of the Prairie Evaporite (Canada), ~4C in radioactive ores, J80 in the analysis of water, 3He in terrestrial rocks, xenon isotopes in pitchblendes, fission track dating calibration, and a proposal for using non- parametric estimations involving small data sets in isotope geoscience. (hbf)

88:3413 Fujinawa, Yukio, Michinori Kubota, Takao Eguchi

and Motoo Ukawa, 1987. A direct recording pop-up type ocean bottom seismograph: CDPOBS lla. Rept natn. Res. Cent. Disaster Prevent., Tokyo, 39:19-35.

This free-fall, pop-up instrument is capable of recording three components of seismic data for 40 days on a 14-channel open-reel magnetic tape recorder. Seismic signals from one vertical and two horizontal 4.5 Hz geophones mounted on a me- chanical gymbal are amplified in three stages and recorded separately. The vertical component is further branched to pass through an equalized amplifier to pick up the low frequency component. After a pre-set time interval or upon receiving an acoustic command, either of two gas-pressure pis- ton-type releasers make the vessel ascend. Posi- tioning of the OBS can be conducted with an acoustic transponder. Natl. Res. Center for Disaster Prevention, Japan.

88:3414 Kim, S.-R., H.-R. Yoo, G.-T. Park, Y.-K. Lee and

C.-H. Ann, 1987. Digital processing and acoustic backscattering characteristics on the seafloor image by side scan sonar. J. oceanol. Soc. Korea, 22(3):143-152. (In Korean, English abstract.)

KORDI, Ansan, P.O. Box 29, Seoul 171-14, Korea.

88:3415 Magnitski, V.A. and E.M. Chesnokov (eds.), 1986.

Geophysics of anisotropic media: the state of the art. Phys. solid Earth (a translation of Fiz. Zemli), 22(11):867-960; 17 papers.

The introduction reviews the development of seismic anisotropy on various scales by considering data on the elastic anisotropy of rock, deep seismic sound- ings, seismic observations on body waves and surface waves; theoretical studies of wave propa- gation, and the causes of the formation of ordered media. The remainder of the papers are presented in four sections treating: theoretical aspects of seismic wave propagation in anisotropic media--wave fields, dispersion, use of the matrix method, and numerical simulation; formation mechanisms of seismic ani- sotropy of the lithosphere--in the ocean upper mantle and at reflecting boundaries; studies using ultrasonic illumination--the acoustopolarization method, in granitoids, in thin-layered models, and in the crystalline basement; and investigations using seismic surveying methods. (hbf)

88:3416 Nakamura, Yosio, P.L. Donoho, P.H. Roper and

P.M. McPherson, 1987. Large-offset seismic surveying using ocean-bottom seismographs and air guns: instrumentation and field technique. Geophysics, 52(12):1601-1611.

Repeatable, closely spaced signal sources from large-capacity air guns and detection and recording of signals using highly flexible, microprocessor- controlled, digital ocean-bottom seismographs give high-quality, large-offset, marine seismic refraction and reflection data readily adaptable to various processing techniques originally developed for seis- mic reflection data. There are several requirements and problems specific to the technique, i.e., bubbly signals from one or two large-capacity air guns are often preferable to bubble-suppressed signals from tuned arrays in identifying weak arrivals at large offset distances. Recorded water-wave signals at near ranges provide precise locations of detectors relative to shots. Inst. for Geophys., Univ. of Texas, 8701 North Mopac Blvd., Austin, TX 78759-8345, USA.

D50. Subsurface structure

88:3417 Kelamis, P.G. (comment), G.G. Drijkoningen and

J.T. Fokkema (reply), 1987. [Discussion ofl 'The