The calm allowed scientists to actually approach the crater to take gas measurements and film the craters from close: Chances increase that the eruption is over, although this is far from certain (read below for more background). With most likelihood, it is part of a normal fluctuation, but nobody can be sure.ĭepth vs time of quakes under La PalmaNo new activity has been reported at the eruption site since it ceased yesterday. Still, a weak increase in the total energy of the seismic activity remains visible for the past 48 hours or so. In other words, most of the apparent increase of quakes is only an increase in detection sensitivity. Now, the very sensitive seismic devices are again able to pick up very small quakes below magnitudes 2, as well as quakes deeper down (whose signals at the surface are much weaker).
This is mostly an artifact caused by the absence of volcanic tremor, which acted as noise during the eruption and was simply hiding smaller quakes in its signal. This apparent increase, however, is mostly in the number of quakes, especially for those in the deeper region around 30-40 km. If looking at the various maps published of recent quakes, it might seem that there is a a strong increase of quakes. In the latter case, the quakes should slowly die out.ĭuring the past 24 hours, there were 3 quakes of magnitudes 3.3-3.5 at 35-36 km depth, in addition to many more smaller quakes (22 quakes of magnitudes 2.0-2.9 and 48 quakes below magnitude 2.0). However, this is far from certain - it could also be adjustments of the system triggered by the massive shifts of masses that has occurred during the eruption. Some doubt remains as to the significance of the continuing earthquake activity: although of low energy and overall on a decreasing trend, it remains significant, and could indicate that magma at depth is still able to pressurize and fracture rocks at depth and create intrusions that might eventually allow it to rise further. Official confirmation when the eruption is declared over will likely need to wait a little longer. The cone only shows mild degassing and no lava flows are active any more. Current tremor amplitude - near zero (image: IGN)For 3 days, no eruptive activity has taken place, and the likelihood that the eruption is actually over is clearly increasing.
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