Field measurements of volcanic gases. Vulcano Island (Italy), Kilauea (Hawaii,U.S.A.), Merapi (Java,Indonesia)

A field gas chromatograph, built in 1978, was used in the field to directly analyse volcanic gases before water vapor condensation. Tested in Vulcano (Italy), Kilauea (Hawaii) and Merapi (Indonesia), this field measurement technique provides the actual composition of the volcanic gas mixture. The technique avoids the depletion of sulfur gases and the dissolution of the acid gases in the condensed water during the cooling. Thus the mixture of H₂S and SO₂ in fumarolic and high temperature gases (up to 819°C) in equilibrium at the emission temperature was examined.     

1988年11月22日甘肃肃南5.7级地震

1.地震的基本参数及序列根据甘肃区域地震台网和全国地震台网测定,这次地震的基本参数是: 发震时刻:1988年11月22日01时46分1.7秒; 震中位置:北纬38°35′,东经99°32′,即肃南县城以南的祁连山中;     

Reviews Monitoring the Comprehensive Nuclear-Test-Ban Treaty: Source Location,edited by Frode Ringdal and Brian L. N. Kennett. Birkhäuser Verlag Basel-Boston-Berlin, 2001, Reprint from Pure and Applied Geophysics (PAGEOPH), Volume 158 (2001), No.1/2, 428 pages

Studia Geophysica et Geodaetica -     

The concentrations of the heavy metals in the four new Antarctic meteorites Yamato (a), (b), (c) and (d) and in Orgueil, Murray, Allende, Abee, Allegan, Mocs and Johnstown

All active midocean ridges show a uniform relationship between depth and age of the oceanic crust. Recently, it has been shown by numerical methods that convective flow in a Newtonian fluid will have a positive gravity anomaly and an upward surface deformation associated with an ascending limb. If there is thermal convection in the upper mantle, these calculations predict that there may be a correlation between free air gravity anomalies and differences from the uniform relationship between oceanic depth and age. To investigate such a correlation, we considered the crestal elevation and free air gravity anomaly over the crest of the midocean ridges. It has been suggested that the differences from the depth versus age relationship are related to spreading rate. Thus, we also considered a correlation between crestal elevation and changes in rate along the ridge axis.We found a positive correlation between free air gravity and differences in crestal depth of the midocean ridge system. We found no correlation between spreading rate and gravity and no uniform relationship which holds in all the oceans between spreading rate and observed crestal depths.The long wavelength gravity anomalies which are correlated with the differences in crestal depth cannot be supported by an 80 km thick lithosphere. Thus, they are considered evidence of flow within the aesthenosphere. Further, the correlation between gravity anomaly and differences in crestal depth has the same sign and gradient as predicted by the investigations of convection in a Newtonian fluid.