Frank Press

Bio: Frank Press is an academic researcher from National Academy of Sciences. The author has contributed to research in topics: Love wave & Lamb waves. The author has an hindex of 11, co-authored 23 publications receiving 4315 citations. Previous affiliations of Frank Press include Executive Office of the President of the United States.

Elastic Waves in Layered Media

Abstract: (1958). Elastic Waves in Layered Media. Geologiska Foreningen i Stockholm Forhandlingar: Vol. 80, No. 1, pp. 128-129.

Excitation of the free oscillations of the Earth by earthquakes

Abstract: The free oscillations of the earth have been experimentally verified from an analysis of strain seismograph and pendulum seismograph recordings made in California and Peru from the great Chilean earthquake of May 1960. Both spheroidal and torsional oscillations were revealed by a power spectral analysis of the seismograms. The gravest spheroidal mode shows a split spectral peak with periods of 54.7 and 53.1 minutes. The theoretical prediction for the Bullen B model according to Alterman, Perkeris, and Jarosch is 53.7 min. The oscillations were observed for all modes up to 38 with corresponding periods as short as 3.7 minutes. For the higher modes, agreement in the observed period is found between the Chilian earthquake and the Kamchatka earthquake of 1952. In almost all cases agreement between experimental and theoretical predictions is close. Differences which occur should make it possible to discriminate between the several earth models which have been proposed. From the width of the spectral peak, values of the dissipation function Q−1 for the earth could be determined with an accuracy greater than was previously possible. For the spheroidal mode S3(T = 35.5 min), Q = 380, and for the mode S18(T = 6.2 min), Q = 170. On the assumption that Q is independent of frequency, this implies a higher Q in the core than in the mantle. A method is described for deducing the fault length and rupture velocity from analysis of phase difference between components of ground motion. Preliminary results indicate a fault length for the Chilean earthquake of about 1000 km and rupture velocities in the range 3 to 4 km/sec.

Patterns of seismic release in the southern California region

Abstract: Southern California experiences earthquakes on the San Andreas system of vertical right-lateral predominantly strike-slip faults and on a second system of faults that includes thrusts, oblique-slip, left-lateral, and other faults. Pattern recognition and cluster analysis are used to analyze the catalog of earthquakes with magnitudes ≥5.5 from 1915 to 1994. We use pattern recognition to find a suite of traits that would characterize each of these two systems and distinguish them from each other. Both pattern recognition and cluster analysis show that epochs of seismic release occur in which one or the other system is the predominant form of earthquake activity. For the past 2 decades the second system has been the active one. Small changes in the direction of plate movements could account for this phenomenon. Seismic release on the San Andreas system is preceded by episodes of activity in the Great Basin or in the Gulf of California. Presumably, these episodes would represent extension in the former region and spreading and slip on transform faults in the latter.

Crustal structure in the California‐Nevada region

Abstract: A case is made for the combined use of three methods for the study of the earth's crust in a given region: seismic refractions, surface wave phase velocity, and gravity. Only by this approach can the fine details of crustal structure be revealed. The standard phase-velocity curves are revised to take into account recent refraction results in South Africa and the Gutenberg low-velocity zone of the upper mantle. Restrictions on the use of the phase-velocity method alone are discussed. In the California-Nevada region seismic refractions reveal the following structure below the sediments: 23 km of granitic rock with velocities of 6.11 km/sec and 3.49 km/sec for compressional and shear waves; 26 km of gabbroic-ultramafic rock with a compressional velocity of 7.66 km/sec underlain by a zone of ultramafic rock with a compressional velocity of 8.11 km/sec. When this structure is used in computing theoretical Rayleigh wave phase velocities and gravity anomaly, discrepancies are found with the observed values which can be resolved by reducing the mean shear velocity and the density in the crust. It is probable that this reduction is limited to the intermediate crustal layer, and several modifications consistent with all three exploration methods are discussed.

Theoretical basis of some empirical relations in seismology

Abstract: Empirical relations involving seismic moment M_o, magnitude M_S, energy E_S and fault dimension L (or area S) are discussed on the basis of an extensive set of earthquake data (M_S ≧ 6) and simple crack and dynamic dislocation models. The relation between log S and log M_o is remarkably linear (slope ∼ 2/3) indicating a constant stress drop Δσ; Δσ = 30, 100 and 60 bars are obtained for inter-plate, intra-plate and “average” earthquakes, respectively. Except for very large earthquakes, the relation M_S ∼ (2/3) log M_o ∼ 2 log L is established by the data. This is consistent with the dynamic dislocation model for point dislocation rise times and rupture times of most earthquakes. For very large earthquakes M_S ∼ (1/3) log M_o ∼ log L ∼ (1/3) log E_S. For very small earthquakes M_S ∼ log M_o ∼ 3 log L ∼ log E_S. Scaling rules are assumed and justified. This model predicts log E_S ∼ 1.5 M_S ∼ 3 log L which is consistent with the Gutenberg-Richter relation. Since the static energy is proportional to σL^3, where σ is the average stress, this relation suggests a constant apparent stress ησ where η is the efficiency. The earthquake data suggest ησ ~ 1/2 Δσ. These relations lead to log S ∼ M_S consistent with the empirical relation. This relation together with a simple geometrical argument explains the magnitude-frequency relation log N ∼ − M_S.

P-SV wave propagation in heterogeneous media: Velocity‐stress finite‐difference method

Abstract: I present a finite-difference method for modeling P-SV wave propagation in heterogeneous media This is an extension of the method I previously proposed for modeling SH-wave propagation by using velocity and stress in a discrete grid The two components of the velocity cannot be defined at the same node for a complete staggered grid: the stability condition and the P-wave phase velocity dispersion curve do not depend on the Poisson's ratio, while the S-wave phase velocity dispersion curve behavior is rather insensitive to the Poisson's ratio Therefore, the same code used for elastic media can be used for liquid media, where S-wave velocity goes to zero, and no special treatment is needed for a liquid-solid interface Typical physical phenomena arising with P-SV modeling, such as surface waves, are in agreement with analytical results The weathered-layer and corner-edge models show in seismograms the same converted phases obtained by previous authors This method gives stable results for step discontinuities, as shown for a liquid layer above an elastic half-space The head wave preserves the correct amplitude Finally, the corner-edge model illustrates a more complex geometry for the liquid-solid interface As the Poisson's ratio v increases from 025 to 05, the shear converted phases are removed from seismograms and from the time section of the wave field

The Laboratory in Science Education: Foundations for the Twenty-First Century

Abstract: The laboratory has been given a central and distinctive role in science education, and science educators have suggested that rich benefits in learning accrue from using laboratory activities. Twenty years have been elapsed since we published a frequently cited, critical review of the research on the school science laboratory (Hofstein & Lunetta, Rev. Educ. Res.52(2), 201–217, 1982). Twenty years later, we are living in an era of dramatic new technology resources and new standards in science education in which learning by inquiry has been given renewed central status. Methodologies for research and assessment that have developed in the last 20 years can help researchers seeking to understand how science laboratory resources are used, how students' work in the laboratory is assessed, and how science laboratory activities can be used by teachers to enhance intended learning outcomes. In that context, we take another look at the school laboratory in the light of contemporary practices and scholarship. This analysis examines scholarship that has emerged in the past 20 years in the context of earlier scholarship, contemporary goals for science learning, current models of how students construct knowledge, and information about how teachers and students engage in science laboratory activities. © 2003 Wiley Periodicals, Inc. Sci Ed88:28–54, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/.sce10106

Stress Waves in Solids

Abstract: A large and growing number of original papers on both the experimental and the theoretical aspects of stress wave propagation is appearing in the scientific literature, and two international conferences solely concerned with the subject have been held during the last five years. The purpose of this paper is to review recent experimental and theoretical advances in the propagation of deformation waves of arbitrary shape through elastic and anelastic solids, and also to attempt to outline the problems on which present efforts are being directed and to predict probable lines of future development.

The Resolving Power of Gross Earth Data

Abstract: A gross Earth datum is a single measurable number describing some property of the whole Earth, such as mass, moment of interia, or the frequency of oscillation of some identified elastic-gravitational normal mode. We show how to determine whether a given finite set of gross Earth data can be used to specify an Earth structure uniquely except for fine-scale detail; and how to determine the shortest length scale which the given data can resolve at any particular depth. We apply the general theory to the linear problem of finding the depth-variation of a frequency-independent local Q from the observed quality factors Q of a finite number of normal modes. We also apply the theory to the non-linear problem of finding density vs depth from the total mass, moment, and normal-mode frequencies, in case the compressional and shear velocities are known.