000193405 001__ 193405
000193405 005__ 20181127114059.0
000193405 044__ $$agw
000193405 041__ $$aeng
000193405 100__ $$aKlokočník, Jaroslav
000193405 24510 $$aA support for the existence of paleolakes and paleorivers buried under Saharan sand by means of “gravitational signal” from EIGEN 6C4
000193405 300__ $$a28 stran
000193405 5203_ $$9eng$$aThe goal of this study is to demonstrate that and how the recent gravitational and topographic data support the findings made by geologists and others as for the existence of the paleolakes and paleoriver systems, now buried under the sands of Sahara. It is always important and useful to have such an independent analysis supporting certain results, and this paper is such a case. We make use of the gravity disturbances (or anomalies), the Marussi tensor of the second derivatives of the disturbing geopotential, the gravitational invariants and their certain ratio, the strike angle and the virtual deformations. The geopotential is represented by the global combined (from satellite and terrestrial data) high-resolution gravity field model EIGEN 6C4 (till degree and order 2160 in spherical harmonic expansion). The topography is derived from the ASTER GDEM and ETOPO 1 models (both are used). With all these data, we confirm the existence of huge paleolakes or paleoriver systems under the Saharan sands known or anticipated in an independent way by geologists for the lakes MegaChad, Fazzan and Chotts; for Tamanrasset river valley; and Kufrah Basin, presumptive previous flow of the Nile River. Moreover, we suggest a part of the Grand Egyptian Sand Sea as another "candidate" for a paleolake and hence for a follow-up survey.
000193405 653_0 $$aGOCE satellite$$aThe Sahara$$aPaleolakes/paleorivers$$aSatellite digital topography models$$aFunctions of disturbing geopotential$$aGravitational field model EIGEN 6C4
000193405 700__ $$aKostelecký, Jan
000193405 700__ $$aBezděk, Aleš
000193405 700__ $$aPešek, Ivan
000193405 7730_ $$92017$$g10(9)$$tARABIAN JOURNAL OF GEOSCIENCES$$w1866-7511
000193405 85642 $$uhttps://www.rvvi.cz/riv?s=jednoduche-vyhledavani&ss=detail&h=RIV%2F00025615%3A_____%2F17%3AN0000011%21RIV18-MSM-00025615
000193405 856__ $$uurn:doi:10.1007/s12517-017-2962-8
000193405 85640 $$uhttp://www.asu.cas.cz/~jklokocn/AJG_2017_Sahara.pdf
000193405 943__ $$aRIV:J
000193405 980__ $$aclanky_vugtk
000193405 985__ $$aanotace
000193405 985__ $$ariv
000193405 985__ $$akosteleckyjan
000193405 985__ $$autvar21