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1.
L. Rybach 《Environmental Geology》1994,24(1):7-11
At first sight, environmental geophysics could be defined as “applied geophysics to solve environmentally relevant geosphere problems.” However, this formulation requires that the depth domain of the environmentally relevant geosphere (ERG) be delimited. Whereas the ERG upper boundary can easily be set at the earth's surface, the lower boundary still needs to be defined. In fact one might ask down to what depth,D, does the environment extend? On the basis of examples from Switzerland, it will be shown that the ERG can stretch over very different depth domains according to the problem in question. 相似文献
2.
The temperature profile of the KTB pilot drillhole, T(z)KTB-PH,is distinctly nonlinear: a temperature deficit ΔT (relative to a linear temperature-depth profile) is especially pronounced in the depth range 500–3500 m. The depth dependence of the deficit, Δ(z) is compared to be anticipated effect of surface paleoclimatic variations, ΔTpc(z), at the drillsite on the temperature profile. The latter can be calculated from available paleo-climatic models. If ΔTpc(z) is added to T(z)KTB-PH, a nearly linear temperature-depth curve results with an average geothermal gradient of 27.9°C/km. This, together with an average vertical thermal conductivity of 3.0 W/mK, estimated from KTB drillcore data, implies a heat flow density at the KTB site of 84 mW/m2. This modelled value is in good agreement with heat flow determinations in the adjacent Eger graben structure (Western Bohemian massif). 相似文献
3.
Ladislaus Rybach 《Pure and Applied Geophysics》1978,117(1-2):75-82
In crystalline rocks seismic velocityV
p
and densityp increase, whereas radioactive heat productionA decreases from acidic to basic compositions. From the velocity-density systematics for crustal rocks at different pressures an empiricalA(V
p) relationship has been derived for the range 5.0–8.0 km/sec which follows the exponential law:A(V
p
)=a exp (-bV
p
), where the numerical factorsa andb depend onin situ pressure. A graph is given by means of which the heat production distributionA(z) can be obtained for any givenV
p
(z) structure.Contribution No. 207, Institute of Geophysics, ETH Zurich. 相似文献
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The effect of regional and local ground water circulation systems on the Heat Flow Density (HFD) field is demonstrated by two examples from Switzerland, one near St. Gall in an area at the northern border of the Alps, and the other northwest of Zurich along the eastern end of the Jura mountains. Detailed HFD maps of both areas slow pronounced high heat flow zones which are attributed to discharge of subsurface water which has migrated laterally over several 10 km. Seepage velocities on the order of several mm/yr have been calculated. Geothermal information is not available about the infiltration zones where low HFD values are expected. Geochemical and isotopic analysis of water samples from springs and drillholes indicates the recharge zones and demonstrates the effect of extensive regional systems. These results indicate that in regions with significant topographic relief HFD mapping can be seriously biased if drillholes are positioned in valleys which correspond to discharge areas with relatively high HFD, whereas the low heat flow zones remain undetected. 相似文献
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L. Rybach 《Environmental Geology》1997,32(2):137-141
Observations in deep drillholes reveal slow but extensive movement of crustal fluids. Geothermal observables and their interpretation
by modelling heat- and mass-transfer yield flow-rates and penetration depths of deep groundwater circulation. As examples,
two sites in Hercynian terranes are examined: 1) northern Switzerland and 2) KTB (Kontinentales Tiefbohrprogramm) in Germany.
Flow rates are of the order of liters per square meter per year for both sites; depth of penetration is different (5 km and
0.5 km, respectively).
Received: 3 September 1996 / Accepted: 17 December 1996 相似文献
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Ladislaus Rybach 《Environmental Geology》2009,58(8):1645-1651
Crystalline basement can contain notable quantities of thermal/mineral waters. Knowledge about their movement and it characteristics
(fluxes, velocities, trajectories) is of great relevance for subjects like waste disposal or geothermal resources. Geothermal
methods enable to quantify these flow characteristics. The use and potential of several methods is demonstrated at three sites,
all from Hercynian basement in Western Europe. The results show rather uniform characteristics: Darcy flow velocities on the
order of 10−11–10−10 m s−1; the domain of flow ranges down to 5–7 km depth. 相似文献
10.