The second stage produced a large hyaloclastite scoria mound erupted beneath the Cordilleran Ice Sheet during the Pleistocene.

The hotspot remains in a fixed position, while the North American Plate drifts over it at a rate of 2 to 3.3 centimetres per year.

However, the last eruption from Nazko Cone could have started forest fires, since there is charcoal inside the tephra layer.

The cause of this seismic activity is believed to be the upwelling of magma because the area is not close to any faults or tectonic plate boundaries.

About 5 seismometers were set up around Nazko Cone to enable scientists to measure the intensities and locations of hundreds of small earthquakes every day.

So-called harmonic tremor is a continuous "rumble" which contrasts with the normal seismic activity of sudden shocks and is believed to be caused by the rapid movement of magma underground.

Volcanic tremor normally indicates an imminent eruption, although it may also be caused by shallow intrusions of magma which do not reach the surface.

Nazko Cone was staked for mining its cinder and scoria in the early 1990s by the Canadian Pumice Corporation, and has since been steadily reduced to produce red industrial aggregate for landscaping.

The wetland at Nazko Cone, however, is mixed organic and lava or ash, and the resultant ecosystem is quite unexpected.