Stratigraphy and Formation of Miyakejima Volcano.

Tsukui, Masashi; Niihori, Kenji; Kawanabe, Yoshihisa; Suzuki, Yuichi

doi:10.5026/jgeography.110.2_156

Cited by 38 publications

(32 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1) and its formation and history of activity are reported by Tsukui and Suzuki (1998) and Tsukui et al (2001). In the twentieth century, it had repeated flank eruptions in 1940, 1962 and 1983, at intervals of about 20 years.…”

Section: Introductionmentioning

confidence: 86%

Earthquake swarms preceding the 2000 eruption of Miyakejima volcano, Japan

et al. 2005

View full text Add to dashboard Cite

The first sign of magma accumulating beneath Miyakejima, an island volcano in the northern Izu islands, Japan, came at around 18:00 on 26 June 2000, when a swarm of earthquakes was detected by a volcano seismic network on the island. Earthquakes occurred initially beneath the southwest flank near the summit and gradually migrated west of the island, where a submarine eruption occurred the next morning. Earthquakes then migrated further to the northwest between Miyakejima and Kozushima, another volcanic island and developed to the most intense earthquake swarm ever observed in and around Japanese archipelago. To better image how the initial magma intrusion occurred, we relocated hypocenters by using a station-correction method and a doubledifference method. The relocated epicenters are generally concentrated near the upper bound of dyke intrusions inferred from geodetic studies throughout the initial stages of the 2000 eruption at Miyakejima from 26 to 27 June 2000. As for seismic activity westward off Miyakejima in the morning on 27 June, hypocenters from both a nationwide seismic network that were relocated by the double-difference method, and those from the volcano seismic network relocated by the station-correction method, formed a very shallow cluster that ascended slowly with time as it propagated northwestward from Miyakejima. This suggests that the dykes have both a radial and upward component of movement.

show abstract

Section: Introductionmentioning

confidence: 86%

Earthquake swarms preceding the 2000 eruption of Miyakejima volcano, Japan

et al. 2005

View full text Add to dashboard Cite

show abstract

“…Most samples are basalt or basaltic andesite. The eruption ages of the samples from Fuji, Miyakejima and Oshima were estimated by historic records, tephrochronological methods and the 14 C method as younger than 3000 years (Miyaji, 1988;Yoshimoto et al, 2004;Tsukui et al, 2001;Niihori et al, 2003;Nakamura, 1964). Descriptions of the samples of 2000 eruption of Miyakejima are in AmmaMiyasaka et al (2005) and Kaneko et al (2005).…”

Section: Samplesmentioning

confidence: 99%

238U-230Th radioactive disequilibrium in the northern Izu arc: (230Th/232Th) in the sub-arc mantle

et al. 2008

Self Cite

View full text Add to dashboard Cite

Major and trace element abundances, Sr and Nd isotopic ratios, and 238 U-230 Th radioactive disequilibria have been analyzed for samples from five volcanoes, Oshima, Miyakejima, Niijima, Teishi Knoll and Fuji, located in the northern Izu arc to investigate across-arc and regional variations of chemical compositions of mantle and fluids expelled from a subducting slab. The abundances and abundance ratios of both fluid mobile and immobile trace elements show across-arc variations.All samples but one have radioactive disequilibria, with ( 238 U/ 230 Th) greater than unity (herein, a ratio in parentheses denotes the activity ratio). The observed disequilibrium is similar to those reported for other arc systems, such as Mariana, Tonga, Kermadec, Chile. It originates from higher mobility of uranium relative to thorium during dewatering of the subducting slab. Th) contributed from sediment melt, which dominates the budget of Th in the sub-arc mantle. It also suggests that influence of fluid addition before the final one had not caused a variation in Th isotopic compositions of the sub-arc mantle.

show abstract

“…is the largest eruption of Miyakejima Volcano within the last 10,000 years. About 0.4 km 3 dense rock equivalent (DRE) of eruptive materials (scoria, explosive breccia, and accretionary lapilli) were produced during the eruption, and the Hatchodaira Caldera was formed (Tsukui and Suzuki 1998;Tsukui et al 2001). After the formation of Hatchodaira Caldera, eruption of basaltic andesitic magma formed the stratocone of Mt.…”

Section: Geological Setting Of Miyakejima Volcanomentioning

confidence: 99%

Caldera collapse during the 2000 eruption of Miyakejima Volcano, Japan

Geshi

Shimano

Chiba³

et al. 2001

Bull Volcanol

229

214

View full text Add to dashboard Cite

A collapsed caldera, 1.6 km in diameter and 450 m in depth, was formed at the summit of Miyakejima Volcano during the 2000 eruption. The collapsed caldera appeared on 8 July, with a minor phreatic eruption, 12 days after seismic activity and magma intrusion occurred northwest of the volcano. Growth of the caldera took from 8 July to the middle of August, with seismic swarms associated with the continuous intrusion of magma northwest of the volcano. The growth rate of the caldera was about 1.4×10 7 m 3 /day, and the final volume of the collapsed caldera was about 6×10 8 m 3 . Major phreatomagmatic eruptions produced a total of about 1.6×10 10 kg (1.1×10 7 m 3 ) of volcanic ash after caldera growth. The caldera structure, and the nature of the eruptive materials of the first collapse on 8 July, suggest that the surface subsidence was caused by the upward migration of a steam-filled cavity, with stoping of the roof rock above the magma reservoir. The diameter of the stoping column was estimated to be 600-700 m from circumferential faults that developed in the caldera floor, and the collapse of the caldera wall enlarged the diameter of the caldera to 1.6 km. The total volume of the caldera and the horizontal diameter of the stoping column gave a subsidence of the caldera floor of 1.6-2.1 km.

show abstract

Stratigraphy and Formation of Miyakejima Volcano.

Cited by 38 publications

References 0 publications

Earthquake swarms preceding the 2000 eruption of Miyakejima volcano, Japan

Earthquake swarms preceding the 2000 eruption of Miyakejima volcano, Japan

238U-230Th radioactive disequilibrium in the northern Izu arc: (230Th/232Th) in the sub-arc mantle

Caldera collapse during the 2000 eruption of Miyakejima Volcano, Japan

Contact Info

Product

Resources

About