When it comes to eruptions, the world’s eyes are focused on the ongoing fires on the slopes of Hawaii’s Kilauea volcano – well, that, or a non-existent supervolcano in Vermont. It’s estimated, however, that at least 20 eruptions are happening at any one time around the world, and now we can add a brand-new one taking place within the Galapagos archipelago.
Sierra Negra, a shield volcano on the island of Isabela – the largest island of all 18 – began erupting on June 26. Fissures have appeared on the flanks of the fiery mountain, and lava fountains and flows can clearly be seen in some fairly dramatic (and photogenic) video footage.
No casualties have been reported, and evacuations have already taken place. Tourists, unsurprisingly, have been barred from visiting it, as per BBC News – but much of the rest of the island is safe to visit.
According to the Geophysical Institute of the National Polytechnic School (IG-EPN), the days leading up to the eruption were marked by an uptick in seismic and infrasound activity, recording the movement of magma up through the crust.
At the same time, a strong heat anomaly in the northern area of the caldera (cauldron-like feature) was detected, which hinted at the emergence of lava. This was spotted on the Chico volcano, a collection of parasitic cones that formed atop a fissure, much like the cinder cone that’s still being built next to Kilauea’s hyperactive Fissure 8.
Then, on June 26 at 1.40pm local time, the eruption really kicked into gear. An ash plume 10.5 kilometers (about 6.5 miles) high soared skywards. Fissures began appearing on the northern flank of Sierra Negra, and lava began pouring into the sea, creating acidic plumes of laze as they did so.
Luckily, the flows weren’t directed toward any agricultural or inhabited areas – but could this change?
It's hard to say. The IG-EPN’s latest advisory noted that “if this process is maintained and there are no new arrivals of magma to the surface the eruption would end in the next few days, otherwise it could take some time.”
The eruption is pretty similar to Kilauea’s, and that’s not surprising: both have similar plumbing, with an upwelling plume of decompressing mantle material causing considerable melting and generating a fair bit of somewhat runny magma.
Sierra Negra isn’t the only Galapagoan volcano that’s erupting at the moment. Around 12 days ago, La Cumbre, another (probably independent) shield volcano, began erupting in a somewhat similar way on the island of Fernandina.
This has presumably got less media attention due to the fact that it’s uninhabited, whereas Isabela is home to around 1,750 people – meaning that the eruption there is a legitimate hazard.
Now, here’s an important reminder for everyone: As with pretty much every single volcanic eruption taking place out there, plenty of rumors will be flying around, so let’s try and nip some in the bud immediately.
No, this eruption won’t cause a megatsunami. No, it’s not going to mess up Earth’s climate. No, it’s not linked to Kilauea's eruption, or Fuego's. No, volcanic activity hasn’t increased recently – it’s just being filmed, documented, recorded, and written about a lot more these days. Cool? Cool.
It’s worth remembering that the Galapagos archipelago, created by volcanism in the first place, is frequently volcanically active. Sierra Negra, for example, last erupted in 2005. With that in mind, then, these two volcanoes are behaving perfectly normally and doing what such volcanoes tend to do – letting off some steam.