Airborne- and Ground Geophysics for exploration and monitoring of coal fires
Report of the project:
Helicopter Lift-Off in Wuhai (China)
Source: BGR
Within the framework of the Sino-German Research Initiative „Innovative Technologies for Exploration, Extinction and Monitoring of Coal Fires in North China” the China Aero Geophysical Survey & Remote Sensing Centre for Land and Resources (AGRS) assisted by the Federal Institute for Geosciences and Natural Resources (BGR) performed in 2004 a helicopter survey using electromagnetics and magnetics over the coal fire area of Wuda, Inner Mongolia Autonomous Region.
Ground Geophysical Measurements in Wuda (China)
Source: BGR. Photo: G. Schaumann
In the following year ground geophysical surveys were carried out in selected parts of the Wuda coal field. The methods applied were VLF (Very Low Frequency) and in particular TEM (Transient Electromagnetics) done by BGR and magnetics done by AGRS and DMT (Deutsche Montan Technologie). The objective of the geophysical surveys was to study and characterize the areas affected by coal seam fires by means of physical parameters. Electromagnetic methods reveal zones of lower resistivities (i.e. higher conductivities) at depth´s corresponding to the layered coal seams and higher resistivities close to the surface. The ground magnetic data display clearly increased amplitudes of the magnetic field intensity over the areas affected by coal seam fires. However, the physical processes leading to this observations are yet not fully understood and require further investigation and joint interpretation approaches with laboratory data of coal samples.
More information can be downloaded here:
- Geophysical Investigation of the Coal Fire Area of Wuda, Inner Mongolia, with electromagnetic and magnetic methods (PDF, 763 KB)
- Poster: Airborne and Ground Geophysical Investigations over the Coal Fire Area of Wuda, Inner Mongolia (PDF, 2 MB)
TEM Measurements in Wuda (China)
Source: BGR