There are always volcanoes erupting on Earth. Likely since the planet was formed over four and a half billion years ago, volcanic eruptions have rocked some part of the planet. Sometimes it might be an explosion only noticed by the wildlife near a remote volcano. Other times, the blast might catch the world's attention and we feel the impacts for months or years. As you sit there reading this paragraph, somewhere between 10-20 volcanoes are doing their thing.
A Planet of Volcanoes
The Smithsonian Institute Global Volcanism Program lists 49 currently active eruptions (as of mid-August). The total number of volcanoes that have erupted in 2023 so far is 66, but only 16 of those are "new" -- that is, eruptions from volcanoes that don't have long-term activity.
Some volcanoes sit at a low simmer, constantly producing small explosions or lava flows, maybe experience an earthquake swarm or heightened emissions of volcanic gases. These restless volcanoes might stay in this state for years or decades. On the GVP list of current eruptions, the activity at Yasur in Vanuatu is listed as starting in 1270 CE! That's over 750 years of eruption! Along with Yasur, there are six volcanoes that have been erupting since the last century: Sheveluch in Russia, Erebus in Antarctica, Erta Ale in Ethiopia, Stromboli in Italy, Dukono in Indonesia and Santa Maria in Guatemala.
Indonesia has the most volcanoes on the current list, with seven. It is followed by Japan, Russia, and Papua New Guinea that have four each. This really emphasizes how active the western margin of the Pacific Ocean is in terms of volcanic eruptions. We can thank the slow destruction of the Pacific Ocean crust (and related plates) under Eurasia for all this volcanic activity.
However, eruptions are found on every continent except Australia right now. They are also scattered across the Pacific Ocean (Hawai'i, Solomon Islands), Atlantic Ocean (South Sandwich Islands) and Indian Ocean (Barren Island).
Volcanic Activity is Not Increasing
Like I said, this is all perfectly normal for the Earth. Unlike what is said in some dark corners of the Internet, volcanic activity is not increasing on our planet. It is our awareness of volcanism has increased.
Taking some GVP data (above), you can see how this is apparent. On one hand, the number of eruptions and active volcanoes appear to have gone up since 1960, especially so after 2000. However, when you look at VEI 3 or larger eruptions -- the type that would be noticed across much of the 20th and 21st century -- those numbers have stayed level.
This means that the overall rate of volcanism has not gone up, but rather our ability to document eruptions that are small (VEI 3 or less). Many times eruptions that small would leave little to no trace in the geologic record and potentially go unnoticed even at volcanoes near population centers.
Eyes in the Sky, Eyes on the Ground
Instead, we can thank our constant ability to observe the planet both from the surface and from space. A great example of this is the recent eruption from Ruby seamount in the Marianas Islands. The eruption, the volcano's first since 1995, was spotted as a discoloration of the Pacific Ocean by NASA's Terra and Aqua Earth-observing satellites. The eruption looks to have started around September 14-15 (see below) and any evidence more or less vanished by September 20-21.
This eruption was likely not particularly large. Prior to our armada of Earth-observing satellites like Terra, Aqua, Suomi, Sentinel, Landsat 8 and 9 and more, no one would have known this eruption happened unless some ship happened to be in the area or an airplane flew over the eruption site -- neither of which are likely in the middle of the Pacific Ocean.
Combine that with the constant webcam surveillance that many volcanoes now possess and you get an apparent increase in activity that is really just capturing the true level of volcanism on Earth. Our planet is unique in the solar system for its level of volcanic activity, only out-erupted by Jupiter's moon Io. Life on Earth may have not even happened without the heat and material emitted by all these volcanoes. It is just another day on our geologically dynamic planet.
