Nishinoshima has entered a period of intense volcanic activity, with frequent explosive eruptions and ash emissions observed in recent days. Its summit crater has extended in the southwest direction, the Japan Coast Guard (JCG) reported on July 1, 2020
On June 12, the Japan Meteorological Agency (JMA) recorded an ash plume up to 1 900 m (6 200 feet) above the summit, which drifted northeast.
JCG conducted flight observations days later, on June 16, reporting that explosions at the volcano generated dense ash plume up to 2 000 m (6 500 feet) above the summit. Blocks were emitted as far as 2.5 km (1.5 miles) away from the crater.
Nishinoshima volcano, taken on June 15, 2020. Image credit: JCG
On June 25, JCG reported strong explosions again on the volcano, with dark ash plume reaching up to 2 600 m (8 500 feet) above the summit.
Volcanic ash extended about 330 km (205 miles) to the northeast.
The latest @copernicusEu #Sentinel3 images clear enough to look at #Nishinoshima activity were captured on June 27th(OLCI) &28th(SLSTR)showing its plume and strong thermal anomaly. #Volcano #japan @DlrSo2 @ESA_EO @SanGasso @elisa_ox @infomitigasi @UEhttps://t.co/YiPoneLqmC pic.twitter.com/G6ODBDMIuC— antonio vecoli (@tonyveco) June 29, 2020
#volcan #volcano #Nishinoshima L'activité éruptive reste très intense: fontaines et coulées de lave /Eruptive activity remains very sustained:fountains source of strong ash emissions, and lava flows. https://t.co/7H2eDDs2io pic.twitter.com/TCwfCp5Q3y— CultureVolcan (@CultureVolcan) June 25, 2020
At 18:00 UTC on June 27 (03:00 LT on June 28), JMA recorded strong eruption, with a dense dark ash plume up to 3 800 m (12 500 feet) above the crater, which drifted northeast.
Nishinoshima volcano, taken on June 29. Image credit: JCG
Image credit: Copernicus EU/Sentinel-3, Antonio Vecoli. Acquired July 1, 2020
The eruptions continued the following day as JCG confirmed active volcanic activity on June 29, noting that the central crater is extending to the southwest.
The volcano was emitting black smoke plume violently, as JCG described, reaching an altitude of more than 3 400 m (11 150 feet).
Lava flowed down the southwest coast and into the sea, it added.
The small island of Nishinoshima was enlarged when several new islands coalesced during an eruption in 1973-74. Another eruption that began offshore in 2013 completely covered the previously exposed surface and enlarged the island again. Water discoloration has been observed on several occasions since.
The island is the summit of a massive submarine volcano that has prominent satellitic peaks to the S, W, and NE. The summit of the southern cone rises to within 214 m (702 feet) of the sea surface 9 km (5.6 miles) SSE. (GVP)
Featured image credit: JCG