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## Diversity, speciation, endemism and extinction in Devonian reef and level-bottom communities, eastern North America

### Coral Reefs (1983-11-01) 2: 65-70 , November 01, 1983

Lower Devonian late Emsian (Bois Blanc and Clear Creek Limestones; Schoharie Formation) level-bottom communities in New York, Michigan and Illinois were moderately cosmopolitan and diverse and dominated by brachiopods and solitary rugose corals. Subsequently (Early Eifelian?), there was an important episode of cratonal patch reef building in New York (Edgecliff Member, Onondaga Limestone), southwestern Ontario (Formosa Reef Limestone, lower Detroit River Group), and the Hudson Bay Lowland (Kwataboahegan Formation) by highly diverse endemic communities. The Edgecliff reefs were built by corals whereas the Formosa and Kwataboahegan reefs were built primarily by stromatoporoids. The strong correlation between high diversity and high endemism during the reef-building episode suggests that these communities contained numberous, small species populations belonging to several major taxa — an example of rapid speciation by geographic isolation and genetic drift.

## Seismic risk of circum-pacific earthquakes I. Strain energy release

### pure and applied geophysics (1983-04-01) 121: 247-267 , April 01, 1983

Commonly used earthquake “whole process” frequency - magnitude and strain energy - magnitude laws are merged to obtain an analytic expression for an upper bound magnitude to regional earthquake occurrence*M*_{3}, which is expressed primarily in terms of the annual maximum magnitude*M*_{1} and the magnitude equivalent of the annual average total strain energy release*M*_{2}. Values of*M*_{3} are also estimated graphically from cumulative strain energy release diagrams. Both methods are illustrated by application to the high seismicity of the circum-Pacific belt, using Duda’s (1965) data and regionalisation. Values of*M*_{3} obtained analytically, with their uncertainties, are in agreement with those obtained graphically. Empirical relations are then obtained between*M*_{1},*M*_{2}, and*M*_{3}, which could be of general assistance in regional seismic risk considerations if they are found to be of a universal nature. For instance.*M*_{3} and*M*_{2} differ by one magnitude unit in subregions of the circum-Pacific.

## International Society for Reef Studies

### Coral Reefs (1983-05-01) 1: 248 , May 01, 1983

## Solar almucantar radiance and aerosol scattering: Springtime data at Kensington, Australia

### pure and applied geophysics (1983-07-01) 121: 749-759 , July 01, 1983

Solar irradiance, skylight, and aureole intensities were measured early in spring 1981 in Kensington, Australia. The aerosol optical thickness, the aureole intensities, and the scattering phase function at 5° suggest that scattering was due to aerosols of very small sizes. The estimates of the weighted aerosol mean square radius,*p*^{2}, seem to lead to the same conclusion.

## Rational use of land for construction in the Tadzhik SSR

### Soil Mechanics and Foundation Engineering (1983-07-01) 20: 135-140 , July 01, 1983

## The amplitude of turbulent shear flow

### pure and applied geophysics (1983-05-01) 121: 391-400 , May 01, 1983

A new formulation of the problem of the statistical stability of fully turbulent shear flow is proposed, in which one seeks mean fields that bound the observed flow from the stable side. In the spirit of maximum transport theory, this formulation admits a larger set of “flows” than are dynamically possible. A sequence of constraints derived from the equations of motion can narrow this set, permitting at each step the determination of a “most stable” field free of any empirical elements. Turbulent channel flow is proposed as the first application and test of this quantitative theory. Past deductive theories for this flow, from “mean field” to “transport upper bounds,” are assessed. It is shown why these theories do not retain the significant destabilizing mechanisms of the actual flow. The implications for turbulent flow of recent work on the nonlinear and three-dimensional instability of laminar shearing flow are described. In first exploration of the “decoupled mean” stability theory proposed here, approximate analytical and numerical stability methods are used to find an amplitude and structure for the averaged flow propoerties. The quantitative results differ by considerably less than two from the observed values, providing an incentive for a more complete numerical study and for further constraints on the admitted class of flows. In the language now current for nonlinear stability theory, evidence is advanced here that an*N*-dimensional central manifold is adjacent to the realized turbulent flow, where*N* has the largest possible value compatible with the dynamical relations.

## Quantitative model of the instability of Kármán's vortex street

### Studia Geophysica et Geodaetica (1983-06-01) 27: 191-202 , June 01, 1983

### Резюме

Зa¶rt;aчa о ¶rt;вuжеnuu u¶rt;еaльноŭ жu¶rt;косmu uссле¶rt;овaнa нa объекmе со срaвнumельно небольшuм чuслом эффекmuвных сmеnенеŭ свобо¶rt;ы. Решенuе оnuрaеmся нa сущесmвовaнuе uнmе*г*рaлов ¶rt;вuженuя, mеорему Лuувuлля об uнmе*г*рuруемых сuсmемaх u связaнное с неŭ квaзunерuо¶rt;uческое (условноnерuо¶rt;uческое) ¶rt;вuженuе сuсmемы нa комnaкmных мно*г*ообрaзuях. Эmu мно*г*ообрaзuя обрaзуюm кольмо*г*оровское множесmво uнвaрuaнmных mоров.

## The airborne laser ranging system, its capabilities and applications

### Bulletin géodésique (1983-03-01) 57: 180-194 , March 01, 1983

The Airborne Laser Ranging System is a proposed multibeam short pulse laser ranging system on board an aircraft. It simultaneously measures the distances between the aircraft and six laser retroreflectors (targets) deployed on the Earth's surface. Depending on the host aircraft and terrain characteristics, the system can interrogate hundreds of targets distributed over an area as large as 6×10^{4} sq. kilometers in a matter of hours. Potentially, a total of 1.3 million individual range measurements can be made in a six hour flight. The precision of these range measurements is approximately ±1 cm. These measurements are then used in a procedure which is basically an extension of trilateration techniques to derive the intersite vector between the laser ground targets. By repeating the estimation of the intersite vector, strain and strain rate errors can be estimated. These quantities are essential for crustal dynamic studies which include determination and monitoring of regional strain in the vicinity of active fault zones, land subsidence, and edifice building preceding volcanic eruptions.

## A three-component sonic anemometer/thermometer system for general micrometeorological research

### Boundary-Layer Meteorology (1983-09-01) 27: 27-42 , September 01, 1983

A three-component sonic anemometer/thermometer system has been developed. It employs single switched transducer pairs and the inverse timed pulse method to yield an absolute calibration. Microprocessor control and use of newly developed transducers give a very small parts cost. The path length of the instrument can be varied from 10 to 15 cm; output is available in digital or analog form. Temperature sensing, via a 5 Μm tungsten resistance element, is integrated into the digital system. Wind tunnel and field results have confirmed the success of the prototype and a set of operational instruments has been constructed.

## Eruption patterns of the chilean volcanoes Villarrica, Llaima, and Tupungatito

### pure and applied geophysics (1983-09-01) 121: 835-852 , September 01, 1983

The historical eruption records of three Chilean volcanoes have been subjected to many statistical tests, and none have been found to differ significantly from random, or Poissonian, behaviour. The statistical analysis shows rough conformity with the descriptions determined from the eruption rate functions. It is possible that a constant eruption rate describes the activity of Villarrica; Llaima and Tupungatito present complex eruption rate patterns that appear, however, to have no statistical significance. Questions related to loading and extinction processes and to the existence of shallow secondary magma chambers to which magma is supplied from a deeper system are also addressed.

The analysis and the computation of the serial correlation coefficients indicate that the three series may be regarded as stationary renewal processes. None of the test statistics indicates rejection of the Poisson hypothesis at a level less than 5%, but the coefficient of variation for the eruption series at Llaima is significantly different from the value expected for a Poisson process. Also, the estimates of the normalized spectrum of the counting process for the three series suggest a departure from the random model, but the deviations are not found to be significant at the 5% level.

Kolmogorov-Smirnov and chi-squared test statistics, applied directly to ascertaining to which probability*P* the random Poisson model fits the data, indicate that there is significant agreement in the case of Villarrica (*P*=0.59) and Tupungatito (*P*=0.3). Even though the*P*-value for Llaima is a marginally significant 0.1 (which is equivalent to rejecting the Poisson model at the 90% confidence level), the series suggests that nonrandom features are possibly present in the eruptive activity of this volcano.