On November 14th of 2022, the U.S. Geological Survey posted a special information statement
on a volcano in the northern Mariana Islands.
They stated that the Ahyi Seamount volcano was most likely erupting, and had been since
perhaps mid October.
Although the ongoing eruption has not been directly observed, there is abundant evidence
that it is ongoing at a volcano with a summit depth of 137 meters or 449 feet below sea
level.
Hydroacoustic signals have for nearly a month been detected which were consistent with a
submarine volcanic eruption in the vicinity of the Ahyi Seamount.
Such stations are widely used to attribute volcanic eruptions which would otherwise be
difficult to directly observe.
Additionally, seismic signals also appeared to be originating from the same source.
And, on November 6th, patches of green tinted discolored water were observed from satellite
which originated from the volcano.
Water discoloration is often used as evidence of an ongoing volcanic eruption such as during
the 2011 submarine eruption of El Hierro in the Canary Islands.
Altogether, all of this evidence means that the Ahyi Seamount is the 5th volcano to be
actively erupting in the United States.
It joins the Pavlof, Great Sitkin, and Semisopochnoi volcanoes in Alaska alongside the Kilauea
volcano in Hawaii.
For context, the Ahyi Seamount volcano is located on the eastern edge of the Philippine
Sea where it is 468 miles north of the island territory of Guam.
Ahyi is one of 19 volcanoes considered to be active by the U.S. Geological Survey in
the US Northern Mariana Islands, with the Farallon De Pajaros volcano to the northwest
and the Supply Reef and Maug Island volcaneos to the south.
While both the Farallon De Pajaros and Maug volcanoes do have islands, no one lives on
them at the present.
Like other volcanoes in the Northern Mariana Islands, Ahyi exists due to a tectonic plate
collision to the east.
There, the Pacific Plate is subducting underneath the Mariana Plate.
The melted material from this collision then migrates upwards until it erupts onto the
surface, forming a chain of volcanoes.
Although the age of the Ahyi volcano is unclear, it could be both described as a shallow submarine
volcano and a stratovolcano.
At the present, an eruption cannot yet be definitively confirmed, but in all likelihood
one is ongoing.
This eruption is likely a small effusive event much like seen at prior eruptions of the volcano
formerly known as Loihi in Hawaii, where lobes of low or medium silica lava are flowing onto
the existing volcanic edifice, forming pillow basalt.
Due to the low resolution of current data, we are unsure whether an eruption is originating
from Ahyi's summit or one of its flank vents.
In other words, an eruption could be occurring at a depth of anywhere between 449 and 9,800
feet.
Although this latest eruption could result in a hazard such a small landslide generated
tsunami, there is not any evidence which points towards this occurring.
And, since the eruption has been ongoing for approximately 1 month, it might be coming
to an end.
In the last 4 days, the U.S. Geological Survey has reported a declining number of hydroacoustic
signals, possibly signaling that the eruption which was only recently detected is decreasing
in eruptive intensity.
This activity could either subsequently rebound or result in the end of the eruption.
This eruption might make the summit of Ahyi Seamount a bit shallower, but with several
hundred feet to go before it reaches the ocean surface it is unlikely to form a new volcanic
island; at least for now.
I would personally recommend keeping a distance of 10 miles or 16 kilometers for ships around
the volcano as we are unsure where the erupting vent or vents are located and this radius
encompasses the entire edifice of the volcano.
Due to lack of people who live nearby, this volcano is rightfully rated by the U.S. Geological
Survey as a very low threat volcano.
It joins 1 and perhaps 2 other actively erupting seamount volcanoes which are Kavachi and the
Kaitoku Seamount.
Thanks for watching!
If you would like to request a specific topic, please leave a comment below!
Additionally, I would like to thank my new youtube member Chris Zonruiter for supporting
this channel!