Displacement barrier heights from experimental nucleation rate data     

Jussi Malila  Antti-Pekka Hyvrinen  Yrj Viisanen  Ari Laaksonen 《Atmospheric Research》2008,90(2-4):303-ICNAA07

Nucleation phenomena have a great importance in many areas of science. However, the main theoretical tool to analyse these phenomena, the classical nucleation theory (CNT), has known weaknesses. A decade ago a nucleation theorem based correction to CNT was developed [McGraw, R., Laaksonen, A., 1996. Scaling properties of the critical nucleus in classical and molecular-based theories of vapor–liquid nucleation. Phys. Rev. Lett. 76, 2754–2757]. We have analysed experimental nucleation rate data of two homologous series of molecular fluids in terms of this scaling relation. Our first results suggest possible universal functional form for correction to the temperature dependence of CNT.  相似文献   

Effects of Major Seismic Events on the Rotation of the Earth   总被引：2，自引：0，他引：2  

Ari Ben-Menahem  Mashe Israel 《Geophysical Journal International》1970,19(4):367-393

  相似文献   

Source mechanism of the 1906 San Francisco earthquake     

Ari Ben-Menahem 《Physics of the Earth and Planetary Interiors》1978,17(2):163-181

Surface-wave amplitudes in the period range 50–100 s at eight European and North American stations, horizontal slip profiles along the rupture zone and the timing of certain events along the fault during rupture time are all engaged in unison to reconstruct the motion at the source. A modified source model is used to accommodate a moving rupture with variable dislocation in the direction of propagation.It is inferred that the rupture started at about 13 h 11 m 55 s GMT near San Juan Bautista and propagated unilaterally northwestward along N35°W over 400 km with an average rupture velocity of 3.5 km/s. At 13 h 12 m 12 s, the dynamic shear front, moving with the rupture speed, hit the Lick Observatory. Then, at 13 h 12 m 18 s, the rupture arrived to the vicinity of the epicenter in the Santa Cruz Mountains given by B. Bolt. There the slip changed sharply from an average of 0.5 m to a high value of 3 m causing extensive landslides and avalanches. At 13 h 12 m 32.5 s two railroad clocks at San Rafael were stopped. Finally, at 13 h 12 m 36 s the offset front hit the Naval Observatory at Mare Island and stopped the astronomical clocks there. Conspicuous surface waves, visible on Wiechert seismograms in Europe in the period range 55–65 s, reflect the true rupture time.The seismic data inversion yields an effective radiation source some 240 km long with an average vertical extent of some 34 km over a total fault length of 400 km ($\text{U}\text{d}\text{S ? 29,000}\text{m km}{}^2\text{or}\text{μ}\text{U}\text{d}\text{S ? 9 · 10}{}^{27}\text{dyn cm}$). It began at the Santa Cruz Mountains and ended some 20 km off coast Point Arena. Thus, due to the nonuniform slip profile, only $\text{3}\text{5}$ of the total fracture length contributed to the far radiation field.Although the product of the average source displacement (over the entire fault) and the vertical extent appears to be fairly well determined from the surface-wave spectrums, the separate values of these entities cannot be uniquely determined. If the average surface displacements (～ 3.2 m) are diagnostic of the entire fault, a vertical extent of H = 34 km is required.Finally, a new analysis of surface waves from the Alaska earthquake of July 10, 1958, the Queen Charlotte Islands earthquake of August 22, 1949 and the Kern County shock of July 21, 1952, enables us to draw parallels between the three biggest major events which occurred along the NE Pacific coast during 1906–1958. A common feature of all of these earthquakes is that vertical failure extents of 30–40 km are implied.  相似文献   

Tectonics,seismicity and structure of the Afro-Eurasian junction — the breaking of an incoherent plate     

Ari Ben-Menahem  Amos Nur  Moshe Vered 《Physics of the Earth and Planetary Interiors》1976,12(1):1-50

  相似文献   

Residual displacements and strains due to faulting in real Earth models     

Moshe Israel  Ari Ben-Menahem 《Physics of the Earth and Planetary Interiors》1974,8(1):23-45

Static displacements and strain fields are computed at the free surface of a gravitating radially-heterogeneous earth model. The numerical results indicate that the fields corresponding to a real earth model differ meaningly with comparison to a homogeneous non-gravitating model.The theory is applied to the Alaskan earthquake of March 28, 1964. The strains recorded at Isabella agree with the calculated values; but those at Kippapa and Green Observatory are larger than the theoretical values. In all cases the observed and calculated values are of the same order of magnitude.  相似文献   

Comments on Abe's “Tsunami and mechanism of great earthquakes”     

Ari Ben-Menahem 《Physics of the Earth and Planetary Interiors》1973,7(2):154-160

  相似文献   

The Force System of The Chilean Earthquake of 1960 May 22     

Ari Ben-Menahem 《Geophysical Journal International》1971,25(4):407-417

  相似文献   

Isotopic insights into smoothening of abandoned fan surfaces, Southern California   总被引：1，自引：0，他引：1  

Ari Matmon  Kyle Nichols 《Quaternary Research》2006,66(1):109-118

Cosmogenic nuclide concentrations measured on abandoned fan surfaces along the Mojave section of the San Andreas Fault suggest that sediment is generated, transported, and removed from the fans on the order of 30-40 kyr. We measured in situ produced cosmogenic ¹⁰Be, and in some cases ²⁶Al, in boulders (n = 15), surface sediment (n = 15), and one depth profile (n = 9). Nuclide concentrations in surface sediments and boulders underestimate fan ages, suggesting that ¹⁰Be accumulation is largely controlled by the geomorphic processes that operate on the surfaces of the fans and not by their ages.Field observations, grain-size distribution, and cosmogenic nuclide data suggest that over time, boulders weather into grus and the bar sediments diffuse into the adjacent swales. As fans grow older the relief between bars and swales decreases, the sediment transport rate from bars to swales decreases, and the surface processes that erode the fan become uniform over the entire fan surface. The nuclide data therefore suggest that, over time, the difference in ¹⁰Be concentration between bars and swales increases to a maximum until the topographic relief between bars and swales is minimized, resulting in a common surface lowering rate and common ¹⁰Be concentrations across the fan. During this phase, the entire fan is lowered homogeneously at a rate of 10-15 mm kyr⁻¹.  相似文献   

The surface energy balance and the mixing height in urban areas—activities and recommendations of COST-Action 715     

Martin Piringer  Sylvain Joffre  Alexander Baklanov  Andreas Christen  Marco Deserti  Koen De Ridder  Stefan Emeis  Patrice Mestayer  Maria Tombrou  Douglas Middleton  Kathrin Baumann-Stanzer  Aggeliki Dandou  Ari Karppinen  Jerzy Burzynski 《Boundary-Layer Meteorology》2007,124(1):3-24

The specific problems of determining and simulating the surface energy balance (SEB) and the mixing height (MH) over urban areas are examined. The SEB and MH are critical components of algorithms and numerical models for the urban boundary layer, though the constituent parts of the SEB and the MH are not routinely measured by national weather services. Parameterisations are thus needed in applications. In this investigation, several recently developed algorithms and models for estimating the SEB and MH were applied to new datasets and assessed. Results are discussed in terms of the need for spatial resolution and the parameters needed to describe the urban atmosphere. Limitations of models are identified and recommendations for further development and observations are given. Having identified gaps in knowledge, key findings from new urban experiments and numerical modelling for the SEB and MH are given. The diurnal cycle for the SEB is significantly different from rural conditions—urban heat storage is needed in urban parameterisations. The urban MH is increased over the rural MH, as shown by several numerical schemes and careful sodar analyses. This work has been carried out within the COST-715 Action “Meteorology applied to urban air pollution problems (1998–2004). COST 715 reached a consensus proposing representatively sited measurements of meteorological parameters and turbulent fluxes above roof-tops, and recognised that such data are needed to improve numerical models of the urban surface processes.  相似文献   

Imaging the Kristineberg mining area with two perpendicular magnetotelluric profiles in the Skellefte Ore District,northern Sweden     

María de los Ángeles García Juanatey  Juliane Hübert  Ari Tryggvason  Laust B. Pedersen 《Geophysical Prospecting》2013,61(1):200-219

New magnetotelluric (MT) data from two perpendicular profiles in the Kristineberg area, northern Sweden, were analysed and modelled. In the Skellefte Ore District, the Kristineberg volcanic hosted massive sulphide (VHMS) deposit mine is one of the largest and deepest (1250 m). Seventeen broadband magnetotelluric stations were installed along two existing seismic reflection lines. The profiles were 6 and 12 km long with 500 m and 1 km site spacing, respectively. The obtained MT transfer functions in the period range of 0.0015–200 s are of fairly good quality. Detailed strike and dimensionality analysis reveal consistent but period dependent, strike directions, indicating a change in the geoelectrical strike with depth. From the two‐dimensional inversion of the determinant of the impedance tensor, two stable conductivity models with good data fit were obtained. The addition of seismic reflection information from the co‐located survey, improved the data fit of one of them. Extensive sensitivity analyses helped to delineate the well resolved regions of the models and to determine the position of pronounced boundaries. The results are in good agreement with previous studies, especially regarding the presence of a deep conductor interpreted as a structural basement to the district. They also reveal with more detail the configuration of the main geological units of the Skellefte Ore District, especially of the ore bearing volcanic rocks and the embedded alteration zones.  相似文献