Ing. Dr Ladislav J. Lukeš

Ohne Zusammenfassung     

Reply to Comment by V. Vavryčuk on “Analysis of the State of Stress During the 1997 Swarm in the Western Bohemia” by A. Slancová and J. Horálek

Studia Geophysica et Geodaetica -     

Revised determination of the paleointensity in the cretaceous from the collection of A.S. Bol’shakov and G.M. Solodovnikov

A large volume of data on the paleointensity H _an obtained by A.S. Bol’shakov and G.M. Solodovnikov is ignored in modern reconstructions because the authors did not indicate whether they used the check-point procedure for the detection of chemical alterations in rocks associated with determination of H _an. The paper presents new values of H _an determined by the Thellier-Coe method with the use of the checkpoint procedure from samples of the Armenian collection of Cretaceous rocks used in published studies of Bol’shakov and Solodovnikov. The new results are close to the published ones and point to a small value of the geomagnetic field in the Cretaceous, thereby corroborating Bol’shakov-Solodovnikov’s hypothesis on a low paleofield in the Mesozoic. Our study of samples of the collection studied confirms the reliability of Bol’shakov-Solodovnikov’s determinations of H _an.     

Comment on the “Analysis of the State of Stress During the 1997 Earthquake Swarm in Western Bohemia” by A. Slancová and J. Horálek (Studia geoph. et geod. 44(2000), 272–291)

Studia Geophysica et Geodaetica -     

Comment on the paper “CAWSES November 7–8, 2004, Superstorm: Complex Solar and Interplanetary Features in the Post-Solar Maximum Phase,” B. T. Tsurutani,E. Echer,F. L. Guarnieri,and J. U. Kozyra,Geophys. Res. Lett. 35 (2008)

The solar sources of the magnetic storms of November 8 and 10, 2004, are analyzed. The preliminary results of such an analysis [Yermolaev et al., 2005] are critically compared with the results of the paper [Tsurutani et al., 2008], where solar flares were put in correspondence with these magnetic storms. The method for determining solar sources that cause powerful magnetospheric storms is analyzed. It has been indicated that an optimal approach consists in considering coronal mass ejections (CMEs) as storm sources and accompanying flares as additional information about the location of CME origination.     

Zur Arbeit des Herrn H. J. Kortmann «Bemerkungen zur Methode der Iterierten Geschwindigkeiten«

Summary The formulas (2) and (3) in the remarks of Mr.Kortmann give us a discrepance to our reflections for a case sure existent.     

Comment on Hearty,P.J. and O'Leary,M.J., 2008. Carbonate eolianites,quartz sands,and Quaternary sea-level cycles,Western Australia: A chronostratigraphic approach. Quaternary Geochronology 3: 26–55

A proposal that the yellow sands which commonly overlie Pleistocene eolianites along the west coast of Western Australia may have their origin from major extensions of inland deserts during times of severe aridity, is refuted on several grounds. The eolianites typically are deeply degraded remnants of the original coastal dunes, which contained a high content of non-calcareous detritus. Hence plentiful residual sand will accumulate during weathering of a dune. Studies on heavy mineral content of the yellow sands have shown that there is an inland ageing trend consistent with local derivation from successive dune belts, and have also pointed to local sources for yellow color in the sand, without need to postulate a distant source. Localized denudations have however occurred, during which sand is blown inland to leave tracts of bared limestone. No remnants of the alleged desert extensions exist in the hinterland of the coastal belt.