There has been a change in the Tokara earthquakes.
Weather News reports (Japanese) that the swarm count first dropped to fewer than a hundred a day and then returned slightly more to the north, near Suwanosejima, an island volcano that erupts frequently — it is, in fact, active now.
It still isn’t clear what is causing the Tokara seismic swarm. As for this new development, as Weather News puts it (via Google Translate) “Suwanosejima has been erupting intermittently, and as of 7:39am today, smoke rose up to 1,800m above the crater. It is not clear at this time whether this is a change in the series of seismic activities in the Tokara Islands, or if it is related to the eruption of Suwanosejima. We must keep an eye on future developments.”
Indeed.
Updates:
December 4, 2025, 6:20 a.m., Pacific: I’m updating all these posts. Here is the current JMA update:
Announced by the Fukuoka Regional Meteorological Observatory and Kagoshima Regional Meteorological Observatory at 16:00 on November 28, 2025
We would like to inform you of the activity status on Suwanosejima from November 21st to 3:00 pm on the 28th.
Volcanic activity status
Volcanic activity continues at the Ontake Crater. Volcanic smoke from the eruption rose up to 1,300 meters above the crater rim. No large volcanic rocks were observed flying in a ballistic trajectory. No explosions occurred during this period.
Fire reflections were observed at night using high-sensitivity surveillance cameras throughout the period.
According to the Suwanosejima Branch Office of the Toshima Village Office, ashfall was confirmed in the village (approximately 3.5 km south-southwest of the Ontake Crater).
Volcanic earthquakes with shallow epicenters near the Ontake Crater and those occurring on the west side of the island have remained low. In the medium to long term, an increasing trend has been observed since around October 2024.
Volcanic tremors have been occurring intermittently.
Continuous GNSS observations have revealed slight fluctuations since October 2024, suggesting an increase in the amount of magma accumulation somewhat deeper on the west side of the island.
Volcanic activity has been ongoing on Suwanosejima for a long period of time, and there is a possibility that large volcanic rocks will be scattered in a ballistic trajectory around the Ontake crater during an eruption…
August 24, 2025, 10:40 a.m., Pacific: Suwanosejima has been erupting frequently, per Tokyo VAAC advisories, but always at low level.
Here is an overhead view of one of the eruptions:
諏訪之瀬島噴火中 pic.twitter.com/w5vuzGKU6O
— Ryusuke IMURA (@tigers_1964) August 23, 2025
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August 17, 2025, 3:42 a.m., Pacific: Here’s a graphic, from a knowledgeable but not official source, showing the relationship between Suwanosejima — the island, upper right, with a red blob on its left (western seismicity) — and the rest of the Tokara Islands swarm, which is ongoing but at a lower frequency in recent weeks:
トカラ列島近海(小宝島付近)の群発地震活動 有感最新8月16日https://t.co/DhaTJBWjVk
諏訪之瀬島で有感の火山性地震発生 最新8月17日https://t.co/cstlKB84sK
気象庁有感地震情報を8月15日暫定値で更新しました。
●気象庁 震央分布図 D40km以浅
8月9日～15日 pic.twitter.com/q5jL5Udnt2— 塩井宏幸 (@HiroyukiShioi) August 17, 2025
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X translation: “Earthquake swarm activity off the coast of the Tokara Islands (near Kodakarajima) Latest felt August 16th
http:// h-shioi.la.coocan.jp/Earthquake/Shi oiNote_2025.htm#JE250621A
Volcanic earthquake felt on Suwanosejima Latest August 17th
http:// h-shioi.la.coocan.jp/Earthquake/Shi oiNote_2025.htm#JV_Suwanosejima
Japan Meteorological Agency’s felt earthquake information has been updated with provisional figures for August 15th. ● Japan Meteorological Agency Epicenter Distribution Map Depth 40km or shallower August 9th to 15th”
August 15, 2025, 5:12 a.m., Pacific: The JMA website still lists the volcano at Level 2. Its most recent update, on the 1th, noted no big changes. Seismicity was reportedly more frequent and they mentioned magma accumulation under the western side.
July 8, 2025, 8:47 p.m., Pacific: A couple hours ago, Weather News reported (Japanese) that the number and magnitude of Tokara earthquakes has dropped somewhat, although the swarm is ongoing still at fairly high numbers and today there have been several 3 and 4-pointers.
They don’t reference the shift in epicenters northward, and they don’t mention Suwanosejima at all, which is encouraging.
There are no new updates yet on the volcano, and per the Tokyo VAAC advisory list, no recent explosive activity.
This area is very remote. I haven’t been able to find a live cam online for it.
Featured image: Japan Coast Guard via Wikimedia, C-SA
Flight To Wonder 