Letter to the editor     

Vincenzo Pane  Robert L. Schiffman  Joseph R. Feldkamp 《国际地质力学数值与分析法杂志》1995,19(2):149-151

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Towards a more habitable Mars — or — the coming martian spring     

Joseph A. Burns  Martin Harwit 《Icarus》1973,19(1):126-130

Two schemes are presented in which matter is moved closer to Mars so as to increase the equinoctal precession period of Mars. In such a way the Martian springs, during which Mars is habitable in the long winter model of Sagan (1971), could be extended and, in fact, prolonged indefinitely. The schemes involve using solar energy to move the satellite Phobos and/or material from the asteroid belt. Difficulties exist with the proposals but they are presented to stimulate discussion.  相似文献   

Thrust faulting and crust—upper mantle structure in East Australia     

Joseph M. Mills  Thomas J. Fitch 《Geophysical Journal International》1977,48(3):351-384

Summary. The mid-crustal earthquake of 1973 March 9 (m_b= 5.5, h ≤ 20 km) located 60 km south-west of Sydney, Australia, provides unambiguous evidence of contemporary thrust faulting in South-eastern Australia — a region of high heat flow and Cenozoic basaltic volcanism. Aftershock locations suggest a steeply dipping fault in the depth range from 8 to 24 km with a lateral extent of about 8 km. The mechanism solution is consistent with a tectonic stress field that is dominated by east—west horizontal compression. A seismic moment of 5.7 ± 10²³± 20 per cent dyne-cm was computed from surface-wave amplitudes. Minimum values of slip and stress drop, 2 cm and 1 bar respectively, were estimated from the moment and a fault size taken' from aftershock locations.
Refinement modelling by a controlled Monte Carlo technique was used to provide unbiased models directly from multimode group velocities. The dispersion of fundamental and higher mode surface waves recorded at the digital high-gain station at Charters Towers, Queensland, and the WWSSN station at Adelaide, South Australia, is satisfied by crust- and upper-mantle models which have neither pronounced S-wave low-velocity zones nor thick high-velocity lids within 140 km of the Earth's surface. These models have subcrustal shear velocities of 4.20–4.32 km/s which are 0.4–0.5 km/s slower than Canadian shield shear velocities (CANSD).  相似文献   

The role of current velocity in structuring eelgrass (Zostera marina L.) meadows     

Mark S. Fonseca  Joseph C. Zieman  Gordon W. Thayer  John S. Fisher 《Estuarine, Coastal and Shelf Science》1983,17(4):367-380

Measurements of velocity profiles, bathymetry, and surface sediment characteristics across eelgrass (Zostera marina L.) meadows yielded information on community development processes and functional attributes of this ecosystem. Height/length ratios of the meadows were positively correlated with tidal current velocity. Low, medium, and high current regimes were separated by surface current velocities of approximately 50 and 90 cm s^?1. Z. marina can tolerate approximately 120–150 cm/sec current velocities in the areas studied. Per cent silt-clay and organic matter content of the surface sediments are negatively associated with shear velocity, suggesting that meadows in high current areas are sources while meadows in low current areas are sinks of autochthonous detritus. Current velocity maintains seagrass meadows at different equilibrium levels (relative climaxes). We theorize these different equilibrium levels provide unequal habitat utilization potentials for the associated faunal community.  相似文献   

Untersuchungen über die horizontale Diffusion in der Nordsee     

J. Joseph  H. Sendner  H. Weidemann 《Ocean Dynamics》1964,17(2):57-75

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The direct reduction of astronomical x-ray spectra     

Joseph F. Dolan 《Astrophysics and Space Science》1972,17(2):472-481

A matrix method is outlined for the reduction of astronomical X-ray spectral data which includes the effects of detector resolution and fluorescent escape phenomena. The differences between this method and the ‘backward reduction’ or multiple grid methods presently employed are discussed.  相似文献   

Mars data analysis program special issue no. 2     

Joseph A. Burns 《Icarus》1981,45(2):263-274

An extended photometric time series in the J and K bands of Neptune has a complex appearance which appears to require the simultaneous presence of three periodicities plus related harmonics in the (J-K) color. The most apparent of the fundamental periods is N1 = 17.73 hr. The two others are at N2 = 18.56 and N3 = 18.29 hr and may be the result of amplitude modulation of a previously reported period of 18.42 hr. We interpret the presence of multiple periodicity as indicating that distinct systems of zonal winds exist on the planet. We argue that these wind systems are probably confined to moderate or high latitudes on the basis of recent omages of the planet taken in a spectral region of strong CH₄ absorption, and, by analogy to the zonal wind systems that exist in Jupiter's atmosphere, deduce a period of rotation for the body of the planet of 18.2 ± 0.4 hr. Zonal wind contrasts of up to 109 m sec^?1 are implied in the atmosphere of Neptune by these observations.  相似文献   

Comets: A special issue of Icarus     

Joseph A. Burns 《Icarus》1981,47(3):301

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A Simple Computer Program for the Determination of Aquifer Characteristics from Pump Test Data     

Joseph C. Holzschuh III 《Ground water》1976,14(5):283-285

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Anonymity     

Joseph A. Burns 《Icarus》1981,48(2):149

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