Details of explosion onsets, however, exhibit short-period variability which suggests that the fragmentation mechanism (bubble bursting) is not identically repeated from event to event; rather, variations such as a stuttering source, multiple bursts or other complexity appear to be common. The image above illustrates the onset of seismic (left panels) and acoustic (right panels) signals for two explosion events, demonstrating parallel degrees of apparent simplicity (top event) or complexity (bottom event) at the onset. Recordings were made at seismic station E1S and co-located microphone E1LI, situated 0.7 km from the lava lake; traces show 2 seconds of data.
Explosions also generate remarkable signals at very long periods and in infrasound.
Knight, R.L., R.C. Aster, P.R. Kyle, A.K. Ameko, and R.R. Dibble, Digital recording of the seismicity of Mount Erebus Volcano, November 1994 - June 1996. Antarctic Journal, 31, number 2; pages 41-43, 1998.
Rowe, C., Aster, R., Kyle, P., Dibble, R., Schlue, J., Seismic and Acoustic Observations at Mount Erebus Volcano, Ross Island, Antarctica, 1994-1998, J. Volcanol. Geotherm. Res., 101, 105-128, 2000.
Rowe, C., Aster, R., Kyle, P., Broadband seismic recording of strombolian explosions at Mount Erebus, Antarctic J. US, 33, 330-334, 2005.
Rowe, C., Aster, R., Kyle, P., Seismic observations at the Mount Erebus observatory: 1997-1998, Antarctic J. US, 33, 335-339, 2005.