The distribution of the
seismicity forms an overall pipe-like structure under the northern slopes of the volcano,
and maps the likely pathway of magma from the mantle, through the crust and
up into the
upper levels of the volcano, where the magma fed the two intrusions in 1994 and 1999.
The intermediate, 1996-seismicity was probably caused by magma intruding
up into the
bottom of the crust
/media/vedurstofan/utgafa/skyrslur/2009/VI_2009_013.pdf