Hugh Tuffen, researcher at Natural Environment Research Council (NERC), has described the Earth's crust as a cause of tectonic earthquakes through his study of lava erupted beneath Icelandic glaciers. The studies have also speculated that gas escaping from magma beneath the surface belches through existing cracks in the volcano, trigger an earthquake. Number of calculations in his study suggested that the size of the faults in Iceland and the size of recorded volcanic earthquakes are directly related to each other. The research also focused to predict the depth magma would fracture and match it with the depth of measured earthquakes, thereby developing a unique facility for breaking rocks at high temperatures and measuring the tiny earthquakes caused by fracturing on a millimeter scale. The measurement of fracturing behavior of a variety of dome samples from different stages of eruption was also highlighted with the help of geophysical observations from volcanoes.