IAVCEI 2013
Scientific Assembly
Forecasting Volcanic Activity
Reading and translating the messages of nature for society
July 20 (Sat) - 24 (Wed), 2013
Kagoshima, Japan

Hokkaido is situated at the junction of two arc-trench systems, the NE Japan and Kuril arcs, both of which have experienced intense volcanism since late Miocene. We will visit central and eastern Hokkaido, where locates at the southern end of the Kuril arc. We will focus on various types of younger volcanoes, calderas (Akan, Kutcharo and Mashu), a volcanic complex (Taisetsu-Tokachi volcano group), and post-caldera volcanoes (Me-Akan and Atosanupuri). These volcanoes have erupted tephra deposits that are widely distributed in Hokkaido. We will investigate these deposits to reconstruct the eruption sequences and magmatic processes. In addition, we will climb Tokachi-dake and Me-Akan volcanoes to investigate their respective structures. We will also focus on the snow-melt lahar associated with the AD 1926 eruption of Tokachi-dake volcano, which caused severe hazards and killed 144 people.

The participants are required to book into a hotel at Asahikawa on July 13 (Sat.) and will be sharing rooms from July 14 to 18. Further details of the field trip will be announced after the application process.

This trip will visit two active volcanoes, Unzen and Aso, in central Kyushu, southwestern Japan, to observe volcanic deposits and study their impacts on the residents around the volcanoes. The 1990-1995 eruption of Unzen volcano resulted in one of Japan’s largest volcanic disasters in the 20th century. Shimabara city and its environs were damaged by repeated pyroclastic flows and lahars. We will climb the new lava dome, visit the devastated area, and observe the 1991-1995 dome-collapse type block-and-ash pyroclastic-flow and lahar deposits. Furthermore, we will examine older deposits around the volcano and discuss the growth history starting from 500 ka.　
Aso volcano, located about 70 km ENE of Unzen, is one of the most beautiful caldera volcanoes in the world. The caldera, which is 25 km north-south and 18 km east-west in diameter, was formed by four gigantic pyroclastic-flow eruptions from 270 to 90 ka. The post-caldera central cones initiated their eruptive activity just after the last caldera-forming eruption and have produced large volumes of fallout tephra layers and lava flows. Nakadake volcano, the only active central cone, is one of the most active volcanoes in Japan. Its recent activity is characterized by ash and strombolian eruptions and phreatic or phreatomagmatic explosions. This field trip will focus on the gigantic pyroclastic-flow deposits related to the caldera formation and the explosive and effusive post-caldera activity of the volcano.

Field boots and gloves are needed for the new lava dome climb. Rain gear and sun protection cream are highly recommended.

Meeting place: JR Kumamoto Station (9:00) or Kumamoto Airport (9:45) on July 15.
Transportation from JR Kumamoto Station or Kumamoto Airport (July 15) to JR Kumamoto Station (July 19), round trip by ferryboat from Kumamoto to Shimabara, aerial tramway at Unzen summit area, Unzen Disaster Museum entrance fee, and all accommodations and meals (except dinner on the 1st and 2nd nights) are included.

This field trip will visit Suwanosejima volcanic island, one of the most active volcanoes in Japan and sometimes called the "Lighthouse of East China Sea." This volcano has been active for more than 50 years, with strombolian to vulcanian activities that emit ash and ballistic ejecta. We will climb the summit of Mt. Otake, 799 m asl, to observe the current activities in the crater (very quiet as of October 2012). We will also visit some of the geophysical monitoring sites in the proximal area and examine the deposit from the 1813 eruption, the largest known eruption of this island. We will focus on some aspects of the proximal facies of the 1813 sub-plinian eruption, consisting of clastogenic lava flows and agglutinate, as well as the distal scoria-fall deposits.
We will take the local ferry “Toshima” from Kagoshima to Suwanosejima island. This boat will pass along the volcanic islands of the Kirishima-Ryukyu arc. We will return to Yakushima aboard the chartered boat “Nanashima 2,” which will go around Suwanosejima, allowing us to see coastal volcanic deposits, and then cruise along the volcanoes of the Tokara islands toward Yakushima island; this area is one of the most popular natural heritage sites in Japan.

Note: The boat trip to Suwanosejima is frequently cancelled or its schedule changed due to bad sea conditions caused by typhoons. This field trip may also be cancelled, even immediately before it starts, if there is a risk of the boat trip being cancelled due to stormy weather. Field boots are needed for the climb. Rain gear and sun protection cream are also highly recommended. There are no shops and banks in Suwanosejima island, only some drink vending machines. The trip fee covers all three meals (mainly Japanese-style seafood) and 4 liters of water daily. Participants should bring any other provisions they would need. The trip ends on arrival at Miyanoura port in Yakushima island (afternoon of July 18). Participants can choose to return immediately to Kagoshima or stay overnight at Yakushima island, which is a famous world heritage site because of its deep forest of old cider. There are several direct ship connections between Yakushima and Kagoshima. Additional information about the ship to Kagoshima, as well as optional tours and accommodations in Yakushima, will be provided.

Northeast Japan, a mature island arc, has many stratovolcanoes along with some other volcano types. Eighteen of these volcanoes are active. Most of the stratovolcanoes in NE Japan are thought to follow a general evolutional course consisting of (1) cone building, (2) caldera collapse, and (3) post-caldera stages. We will visit the following six active volcanoes and observe the geologic features of their activities during various evolutional stages: the Iwate volcano, which is in the cone-building stage; the Bandai volcano, which is in the caldera-forming stage; and the Azuma, Zao, Akita-Yakeyama, and Hachimantai volcanoes, which are in the post-caldera stage. The latest eruptions took place in AD 1888 at Bandai, in AD 1977 at Azuma, in AD 1940 at Zao, in AD 1919 at Iwate, and in AD 1997 at Akita-Yakeyama. Among these, the 1888 eruption in Bandai is famous for a sector collapse that accompanied a debris avalanche phenomenon, which was the first ever reported in the world. Around Akita-Yakeyama, one can enjoy a spectacular view of a geothermal field. We will also visit Ichinomegata maar (80 to 60 ka), which features mantle xenoliths, and the Toga tuff ring.

The excursion will end at the Karuizawa station (Nagano Shinkansen) on the evening of July 29.

Asama volcano, located near the Tokyo metropolitan area, is one of the most active volcanoes in Japan. It has had frequent vulcanian eruptions since the beginning of the 20th century, and small eruptions recently occurred in AD 2004 and 2009. We will investigate the eruptive history of the volcano, including stratovolcanoes, pyroclastic cones, and lava domes. Focusing on its famous, great eruption in AD 1783, we will discuss the eruption style based on the latest research on the proximal depositional processes of pyroclastic materials to form pyroclastic cones and clastogenic lava during a plinian eruption. We will also discuss how the volcanic edifice grows through such proximal processes.

Fuji and Hakone volcanoes, on the northern end of the Izu-Bonin-Mariana arc, are famous sightseeing spots in Japan because of the great views, hot springs, and many amusement facilities in their surrounding areas. However, both Fuji and Hakone are active volcanoes with potential hazards. The field trip will visit the AD 1707 Hoei crater and the AD 864-866 lava flows of Fuji volcano and the active fumarole vent of Hakone volcano.
  The AD 1707 plinian eruption was the most explosive activity of Fuji volcano. The eruption began at the SE flank, and its fallout was dispersed eastward toward Tokyo. The volume of tephra was estimated to be 0.7 km3 DRE. The AD 864-866 lava flow was one of the most voluminous in Fuji volcano. The lava was extruded from fissure vents at the NW flank, and its volume reached 1.5 km3 DRE. Hakone volcano, located east of Fuji, is accompanied by a 10-km-diameter caldera and central cones. There are many hot springs within the caldera. We will visit the Owakudani tourist site and observe the fumarolic activity of Hakone volcano.

This trip visits two topographically and petrologically contrasting active volcanoes in the Izu islands, the basaltic Izu-Oshima and the rhyolitic Niijima volcano. Izu-Oshima has erupted more than a hundred times during the last 20,000 years. Its latest 12 eruptions in the past 1,500 years, including the caldera formation, have been well investigated. We will view a spectacular tephra sequence, the caldera topography, and a chain of fissure vents. In view of the continuing inflation of the volcanic edifice on the island, we will visit the well-equipped observation stations and see how data are monitored in preparation for any forthcoming eruption. Niijima volcano consists of more than 16 rhyolite lava domes. The recent products of dome-building eruptions, such as pyroclastic surge and flow deposits, fallout pumice, and dome lava, are exposed along the sea cliff and quarry. We will closely observe the pyroclastic materials and their depositional structures, which suggest eruptions in the shallow submarine to subaerial environment.

This trip covers two active volcanoes in southern Kyushu, Kirishima and Sakurajima, where volcanic deposits and their impacts on residents can be observed. We also look at some large-scale ignimbrites and their source calderas. Sakurajima is a post-caldera volcano of the Aira caldera, which produced a vast ignimbrite plateau in southern Kyushu in ca. 30 cal KBP. Kirishima consists of more than 20 vents, which are also post-caldera volcanoes of the Kakuto caldera. Shinmoedake, one of the active post-caldera volcanoes, erupted sub-plinian pumice in January 2011. We can observe the new tephra deposit at the foot of the volcano.

Participants are required to extend their stay for one more night, i.e., on July 25, by yourself.

The Kikai caldera is one of the most active volcanoes in Japan. Most of the caldera is now submerged except for two major islands, Satsuma Iwo-jima and Take-shima. The last caldera-forming eruption, called the “Akahoya eruption,” occurred 7,300 years ago. This eruption produced voluminous pyroclastic flows (Koya ignimbrite) and widespread ashfall (Akahoya ash), which had devastating impacts on the culture and natural environment of western Japan. After this eruption, new volcanoes formed inside the caldera through bimodal magmatism. One of young silicic cones, Iwo-dake, has continued to emit volcanic gases for hundreds of years. On this field trip, we will visit Satsuma Iwo-jima island and southern Kagoshima area to observe the eruptive products from the Kikai caldera, mainly focusing on pyroclastic deposits (plinian fallouts and ignimbrites with various lithofacies) from the Akahoya eruption, and young tephra and lava flows from post-caldera volcanoes. Two young volcanoes (the silicic Iwo-dake and the basaltic Inamura-dake) in Satsuma Iwo-jima island make for a spectacular scenery. The recent activities, deposits, and current landscape represent the evolution of a large silicic magmatic system beneath the sea. We will also visit silicic pyroclastic deposits from the Ikeda caldera in Ibusuki area.

Note: Stay at a Minshuku (Japanese-style accommodation) in Satsuma Iwojima island. The final schedule will be decided depending on the weather and sea conditions, which are basically good during this season, except for occasional typhoons.

  The Kamchatka peninsula hosts a highly active and explosive volcanic arc, which forms the northwestern part of the Pacific Ring of Fire. Our field excursion will concentrate on the Holocene volcanism, with a special focus on recent tephra deposits. The highlights of the excursion include trips to the most active and prolific volcanoes of the arc. Near the city, we will be able to see the Avachinsky and Koriaksky "home volcanoes" and examine their Holocene deposits. Then we will drive 500 km northward toward the Kliuchevskoi volcanic group, which comprises the largest Kamchatka volcanoes. Kliuchevskoi (4850 m asl) is one of the most productive volcanoes on Earth, erupting an average of about 90 Mt of magma every year. Ash clouds shooting from the volcano reach an altitude of ~20 km and regularly affect the air traffic between SE Asia and North America. Tephra from Kliuchevskoi, as well as other volcanoes, has been accumulating on its slopes over the last 12 kyr at a rate of ~1 mm/yr. This tephra sequence represents one of the longest and highest resolution record of explosive volcanism in Kamchatka. We will examine tephra deposits and visit a number of Kliuchevskoi’s flank cinder cones and their lava flows. Then we will go to the Tolbachik monogenetic lava field, from where we can climb Plosky Tolbachik volcano (3085 m asl) to see its summit caldera and then visit the cinder cones and lava flows of the monogenetic field, including those formed during the 1975 eruption. The trips will be guided by volcanologists from the Kamchatka Institute of Volcanology and Seismology.
  Air carriers from Japan to Kamchatka: Vladivostok Airlines to Vladivostok, overnight stay, and then proceed to Petropavlovsk-Kamchatsky. Airport transfers to/from guest houses in Yelizovo on arrival/departure. Accommodation: Guest houses in Yelizovo, on arrival and before departure (twin rooms, shared baths). City tour and visit to Paratunka geothermal spa area. Transportation by chartered bus on the main roads and by truck on the slopes of the volcanoes. Guest house accommodation in Kozyrevsk village (near Tolbachik). Tent camping on the volcanoes. Easy short hikes to tephra outcrops and optional more serious hike to Plosky Tolbachik. More excursions are available on request and at an additional cost, including to the Valley of Geysers, the Uzon caldera, the Kurile Lake caldera, and a marine tour.

Contact:  Martha Madsen, Explore Kamchatka, www.explorekamchatka.com, explorekam@gmail.com
The costs depend on the number of participants. Minimum group size of 6, maximum of 16.  Price per person for a group of 6: $3,497. Price per person for a group of 16: $1,899.
The costs include: airport transfers, accommodation in Yelizovo and Kozyrevsk, meals, transportation, visa assistance, all permits, fees, English-speaking staff, and tents.

Changbaishan volcano is the biggest and has the greatest potential eruption risk among all the active volcanoes in China. Tianchi (Sky Lake), the highest volcanic pond in the world at an elevation of 2,744 meters, is situated in the 5-kilometer-wide caldera known as Mount Paektu in Korea. During this trip, we will visit the caldera summit, a waterfall on the north flank, a pyroclastic valley, an underground forest, a stone forest formed in the pyroclastic deposit, etc. Finally, we will stop at the Changbaishan Volcano Observatory for a brief seminar on the current volcanic activity of Changbaishan volcano based on monitoring data.