Microwave observations of Saturn's rings: anisotropy in directly transmitted and scattered saturnian thermal emission     

David E. Dunn  Lawrence A. Molnar  Imke de Pater 《Icarus》2004,171(1):183-198

We present a new Very Large Array (VLA) image of Saturn, made from data taken in October 1998 at a wavelength of λ3.6 cm. The moderate ring opening angle (B≈15°) allows us to explore direct transmission of microwave photons through the A and C rings. We find a strong asymmetry of photons transmitted through the A ring, but not in the C ring, a new diagnostic of wake structure in the ring particles. We also find a weak asymmetry between east and west for the far side of the ansae. To facilitate quantitative comparison between dynamic models of the A ring and radio observations, we extend our Monte Carlo radiative transfer code (described in Dunn et al., 2002, Icarus 160, 132-160) to include idealized wakes. We show the idealized model can reproduce the properties of dynamic simulations in directly transmitted light. We examine the model behavior in directly transmitted and scattered light over a range of physical and geometric wake parameters. Finally, we present a wake model with a plausible set of physical parameters that quantitatively reproduces the observed intensity and asymmetry of the A ring both across the planet and in the ansae.  相似文献   

Gravitational (Rayleigh-Taylor) instability of a layer with non-linear viscosity and convective thinning of continental lithosphere   总被引：8，自引：0，他引：8  

Gregory A. Houseman  Peter Molnar 《Geophysical Journal International》1997,128(1):125-150

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Rupture zones of great earthquakes in the Himalayan region   总被引：1，自引：0，他引：1  

Peter Molnar  M R Pandey 《Journal of Earth System Science》1989,98(1):61-70

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Microearthquake seismicity and active tectonics of northwestern Greece     

G.C.P. King  A. Tselentis  J. Gomberg  P. Molnar  S.W. Roecker  H. Sinvhal  C. Soufleris  J.M. Stock 《Earth and Planetary Science Letters》1983

We carried out a microearthquake survey lasting for six weeks in northwest Greece using 18 portable seismograph stations to examine a region in which normal and thrust faulting have been reported in close proximity to one another. With this array we located 148 events and determined fault plane solutions for eight events using only rays radiated upwards. The seismicity of the region is diffuse with events extending to depths of nearly 30 km, and there is a minimum in activity near a depth of 15 km. The fault plane solutions exhibit a wide spectrum of fault types and orientations and are not consistent with simple zones of shortening or extension. Neither tractions applied to the edges or bottom of the region nor deviatoric stresses that compensate for lateral variations in crustal thickness can account for the variety of fault plane solutions. We think that the complicated behavior is a manifestation of inhomogeneous deformation due, at least in part, to a pre-existing complicated juxtaposition of structures and formations.  相似文献   

A possible dependence of tectonic strength on the age of the crust in Asia   总被引：2，自引：0，他引：2  

Peter Molnar  Paul Tapponnier 《Earth and Planetary Science Letters》1981,52(1):107-114

In Asia, the intensity and style of active tectonics appears to depend on the age of the last orogenic activity. The shields have remained essentially undeformed during the India-Eurasian collision, but Paleozoic and Mesozoic orogenic belts apparently have been reactivated by this collision, with a suggestion of greater reactivation and more diffuse deformation of the younger belts. If the greater observed heat flow in regions of more recent orogenic activity reflects, at least in part, a greater heat flow from the mantle beneath the younger belts, then the temperatures in the mantle beneath the younger belts should be higher than beneath older belts and shields. Because of the strong dependence on temperature of the creep strength of minerals, particularly of olivine, the crust and mantle beneath the hotter, younger belts should be much weaker than those beneath older belts. This difference in temperature, and consequent difference in strength, may be the cause of the greater reactivation of younger belts.  相似文献   

The rotation group in plate tectonics and the representation of uncertainties of plate reconstructions     

J. Stock  P. Molnar  T. Chang 《Geophysical Journal International》1990,101(3):649-661

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The Origin of Outer Topographic Rises Associated with Trenches     

Barry Parsons  Peter Molnar 《Geophysical Journal International》1958,1(4):707-712

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Magnetic Anomalies, Bathymetry and the Tectonic Evolution of the South Pacific since the Late Cretaceous   总被引：3，自引：0，他引：3  

Peter Molnar  Tanya Atwater  Jacqueline Mammerickx  Stuart M. Smith 《Geophysical Journal International》1975,40(3):383-420

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Excited lines in the H and K region of Ca ii in the solar flare on March 12, 1969     

Gallegos  H. Grossi  Molnar  H.  Seibold  J. R. 《Solar physics》1971,16(1):120-124

Many excited lines and a remarkable emission in the continuum were observed in the region around the H and K lines during a strong flare.  相似文献   

Fault plane solutions of earthquakes and active tectonics of the Tibetan Plateau and its margins   总被引：18，自引：0，他引：18  

Peter Molnar  Hélène Lyon-Caent 《Geophysical Journal International》1989,99(1):123-154

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