Record details

    Subsurface temperature changes due to the crustal magmatic activity - numerical simulation
Statement of responsibility
    Jan Šafanda, Vladimír Čermák
    Čermák, Vladimír
    Šafanda, Jan
Source title - serial
    Studia geophysica et geodaetica
    Roč. 44, č. 2
    s. 327-335
    6 obr., 8 bibl.
    Zkr. název ser.: Stud. geophys. geod. (Praha)
Subject group
    chebská pánev
    gradient geotermický
    model matematický
    sedimenty klastické
    zemětřesný roj
Geographical name
    Nový Kostel (Cheb)
Abstract (in english)
   Geothermal aspects of the hypothesis, relating the earthquake swarms in the West Bohemia/Vogtland seismoactive region to magmatic activity, are addressed. A simple 1-D geothermal model of the crust was used to assess the upper limit of the subsurface heating caused by magma intrusion at the assumed focal depth of 9 km. we simulated to process by solving the transient heat conduction equation numerically, considering the heat of magma crystallization to be gradually released in the temperature interval 1100řC to 900řC. The temperature field prior to the intrusion was in steady-state with a surface temperature of 10řC and heat flow of 80mWm-ř, the temperature at the 9 km depth was 270řC. The results suggest that the temperature and heat flow in the uppermost 1 km of the crust bewgin to grow 100 ka after the intrusion emplacement only, and that the amplitudes of the changes for the realistic lateral extennt (a few kilometres) of the intrusion are very small.
   It was also found that the rate of magma solidification depends strongly on the thickness of the intrusion. It takes about 100 years for a 50 m thick sill to cool down from 1100řC to 600řC, which value represents the lower limit of the solidus temperature. the same cooling takes only 60 days if the sill is 2 m thick. If nature of the strongly reflected boundaries interpreted from the January 1997 Nový Kostel seismograms, is connected with the fresh emplacement of magma, the calculated cooling rates have a predictive potential for the temporal changes of the waveforms
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
Entered date
    31. 3. 2008
Import date
    8. 8. 2012