Hole-to-surface seismic reflection surveys for opencast coal exploration

Opencast coal mines in such a densely populated country as the UK are mostly of small size by world standards, but they are highly profitable. Annual production of opencast coal is currently about 17 million tonnes, constituting some 20% of the UK coal industry's total output. Transport costs are low as the coal is produced for domestic consumption, and consequently opencast coal is a very important national resource.