Ethiopia Experiences Massive Dike Intrusion

 In the Afar region of Ethiopia, a large rifting and seismic event has been ongoing now for several weeks. Earthquakes ranging up to magnitude 5.4, with thousands of smaller quakes have been detected in the region between the Fentale and Dofen volcanic systems in the Awash Basin. 

INSAR images have revealed a series of dikes, with the central dike being some 44km or longer in length. In the meantime on the ground, there are videos and reports of mud volcanoes spewing hot mud and gasses, creating new 'moats' around the region. Satellite images have also recorded a progressively larger heat and gas anomaly within the crater of Fentale.

The system exists in an are of Africa which is rifting to eventually split off from the main continent. The system constantly spreads apart over the years, resulting in earthquakes and volcanic eruptions when magma rises to fill the gaps left by the tectonic spreading. 

It is unclear whether this activity, which as of this writing has diminished to one or two larger quakes per week, down from dozens, will result in a volcanic eruption. However this scenario can't be ruled out, and a reduction in large quakes isn't necessarily a good thing. Also to be considered is that large quakes in the region aren't detected by local instruments. International USGS sensors pick up, generally speaking, any quake around 4.3 and above, so it is likely many smaller quakes are not felt, and not recorded by any local instrumentation.

In Iceland's Reykjanes peninsula, the unrest Northeast of Grindavik was preceded by months of large quakes, which diminished greatly before the eventual eruptions at the Sundhnukagigar fissure series. This was interpreted in Iceland as meaning that the crust was weakened by the large quakes, thus the magma had an easier path to the surface, creating smaller quakes, before the eruptive episodes. Each successive eruptive episode thereafter (continuing now for several years) has been preceded by less and less volcano-tectonic activity before an eruption. Currently, the system is inflated at an eruptible level, however it has not displayed any large quake activity, and the last several eruptions occurred with swarms of less than mag 2.0 before erupting.

So the crisis in Ethiopia is likely not over yet. It could be weeks or months before an eruption, but an eruption cannot be ruled out. It is likely that the dike intrusion has slowed, but this could only mean that the intrusion is finding ways to expand laterally rather than horizontally while it adjusts to the new room underneath the crust that it freed up. It is likely that inflation may resume or result in an eruption at any time, given the sheer size of the intrusion.

It is also possible that the crisis slowly ends without an eruption and simply results in the surficial changes that have already occurred becoming more permanent. Due to the lack of on-the-ground coverage and observations, almost all of this is speculative, at best. But it is an educated speculation that what is now happening in Iceland is a small analog for the large thing that is happening in Ethiopia.