October 2002

Conduit drilling rig site and access road to the rig site have been prepared.

Rig site for conduit drilling (new RS-3, 850 m in altitude), 50 m long and 40 m wide. The well entrance in middle right. Water pool is on left. Rig site for pilot hole (USDP-3) is also used for water pool.

Access road to the rig site, newly constructed. In total, about 4-km long road was constructed or repaired.

Sepember 16, 2002

Weekly reports on conduit drilling through Tohoku Geothermal Energy Co. Ltd. (TGE) started.

Aug 2002

Drilling of water wells for USDP-4 began. Pipe lines installation is scheduled during October-January. Rig site preparation is during October to November.

July 2002

Construction of new raod leading to the conduit drilling site (new RS-3; USDP-3) began in July. Pavement of the road starts in September and ends in December.

April 2002

Additional financial support to USDP was agreed in EC.

The second phase of USDP (the conduit drilling phase) started in renewal system.

January 2002

International symosium, "Unzen Workshop 2002: results of flank drilling and aim of conduit drilling", was held at Shimabara during 26-29 January 2002. Over 70 scientists including 15 foreigners attended. The planning of the conduit drilling was introduced and discussed by attendees.

Group photos in front of a Japanese-style inn at Unzen (left) and near the conduit drilling site (right)

October 2001

Assembly of Governors (AOG) of ICDP supported the EC's last decision, that ICDP supports the Unzen Scientific Drilling Project.

July-August 2001

Operation of USDP-2 ran at Shin-Onokoba following that of the previous year. The bottom depth reached 1,462 m. Drilling penetrated reached the basement of Unzen volcano at 1,182 m-depth, penetrating a layer of hot spring.

Mid-February, 2001

Road construction to the drilling site of pilot hole finished, and the rig installation for a slant drilling of about 400-m long began.

February 9, 2001

Prof. Emmermann and Dr. Lauterjung of ICDP visited the drilling site (USDP-2) and pilot-hole site for conduit drilling, guided by S. Nakada and H. Shimizu.

February 2001

Drilling at Shin-Onokoba (USDP-2) finished, reaching the 900-m below the surface. Additional 500-m drilling is scheduled next year.

End of January 2001

Science meeting to investigate drilled cores from USDP-2 was held at the drilling site of Shin-Ohnokoba.

Early January 2001

Full proposal to ICDP was submitted. Unzen Scientific Drilling Project (USDP) - Investigation of eruption mechanisms through scientific drilling into a volcanic conduit- by Setsuya Nakada, Kozo Uto, John C. Eichelberger, Hiroshi Shimizu, and Sumio Sakuma

December 2000

In consequence and in response to an application that we submitted immediately following the second workshop, STA decided to fund a pilot conduit hole. Around 400-m in slant drilling has been scheduled at RS-3 in January to March 2001.

October-November 2000

Executive members of the USDP decided new RS-3 (northern slope of Mt. Fugen, about 750 m in altitude) as the most possible site for conduit drilling and discussed a plan for the pilot hole for conduit drilling at RS-3 (northern slope of Mt. Fugen, about 700 m in altitude). The importance of drilling a pilot hole was emphasized in the second workshop. Knowledge of the geological structure and water condition near the mouth of the conduit hole is critical to designing the drilling strategy and preparing detailed drilling plans. The hole can be also used for re-injection of spent drilling fluid during conduit drilling.

2-4 October 2000

THE UNZEN SCIENTIFIC INTERNATIONAL DRILLING WORKSHOP (USIDW) was held in the city of Shimabara, as the activity of the second research group of the USDP that deals with planning of the conduit drilling. This workshop was sponsored by Science and Technology of Japan and ICDP; the preproposal of USDP submitted in January 2000 involved the financial support of it. This was supported by the city of Shimabara as well as the first Unzen Scientific Workshop in 1996 that was also sponsored by ICDP.

Totally 32 people including 15 foreigners discussed the technical probability of the conduit drilling. Experts and managers of drilling, coring, and logging from several companies and associations, including Dynatec, Dosec, QD Tech. Inc., Deutag, Devico, Alpexplo etc. were invited. Some of them voluntarily attended (Shulunberger, NED, etc). Three persons from GFZ also attended as the support team of ICDP.

Group photo of WS

On the first day, after introductions of the outline of USDP project and scientific targets of the conduit drilling, three of four candidate sites for the conduit drilling were inspected. The USDP-2 site where the second flank drilling just began was also visited. On the second day, the drillers introduced their techniques related to the conduit drilling and drilling scientists introduced the technical problems during drilling. On the third day, three groups (Alpexplo, Devico+NED+JMC, and DOSECC+Dynatec) proposed the drilling plans to fulfill the minimum of scientific targets.

The products of this workshop are the ICDP newsletter and full proposal of January 2001.

September 2000

The second flank drilling started at Onokoba, along the Mizunashi River, on 25 September. Drilling in the deeper level is scheduled in 2001. The drilling aims the basement 1400 m below the surface.

28-29 June 2000

Western Pacific Geophysical Meeting (WPGM) was held in Tokyo, where the special session, Under the Volcano: Insites from Drilling and Surface Observations, related to the USDP was organized (co-convenors: S. Nakada, K. Uto, J. Eichelberger, and H. Shimizu). Eighteeen oral and 10 poster presentations.

17-18 May, 2000

Environment Assessment of the Azamidani (probable conduit drilling site) in the spring season was carried out. The project had received the permissions for the survey from Agency of Environmenton 28 April and from Agency of Culture on 12 May .

April 22-23, 2000

Geological discussion on drilling cores (USD-1a) and sampling by geological and petrological scientists were done in the Geological Survey of Japan. Images of the cores are pasted in the following site.

Images and geological interpretation of all cores (USD-1a)


Science Advisory Group (SAG) of ICDP decided supporting Technical Workshop in Shimabara this October, submitted as pre-proposal of USDP in January 2000.

March 28, 2000

Finish coring down to 750 m at Minami-Senbongi (USD-1a). Physical logging followed the coring. Layers of pumice-flow deposits and -fall deposits were discovered, implying explosive eruptions in the initial stage of Unzen volcano, being contrast to the recent effusive eruptions.

March 1, 2000

Open house at the Minami-Senbongi drilling site (Shimabara) was visited by more than 400 people on February 26.

Photos of open house.

February 14, 2000

Archives of core samples from the first flank drilling (Minami-Senbongi, depth 105-340 m). Samples in this span contain lava flows, pyroclastic flow deposits, and lahar deposits. Images are posted in a site of Geological Survey of Japan.

February 7, 2000

Open house of USDP project is held on February 26 at the Minami-Senbongi drilling site by Science and Technology Agency and Geological Survey of Japan; co-sponsored by Shimabara Earthquake and Volcano Observatory, Kyushu University, and Geo-E Co. Ltd., and supported by Nagasaki Prefecture and Shimabara City. Tours for explanation by geologists and drilling engineers are scheduled.

January 21, 2000

Archives of core samples from the first flank drilling (Minami-Senbongi, depth 0-105 m). Posted in a site of Geological Survey of Japan.

Images of all core samples of every 3 m-long

Ibid (x2)

Extra photos during drilling and core description

January 12, 2000

Preliminary proposal ("UNZEN SCIENTIFIC DRILLING PROJECT (USDP): INTERSECTING A HIGH-TEMPERATURE VOLCANIC CONDUIT" by S. Nakada, J. Eichelberger, K. Uto and H. Shimizu) was submitted to ICDP. In this preproposal, we ask for financial support for an international technical workshop (in Shimabara, September 2000). Real proposal of a joint project for conduit drilling is scheduled to submit in January 2001.

December 22, 1999

Drilling derrick mast for the 750-m hole stood in Minami-Senbongi. Back is the northeastern veiw of Heisei-Shinzan (1991-95 lava dome). Courtesy by Takeshi Matsushima, Shimabara Earthquake and Volcano Observatory.

December 6, 1999

Operation of the first flank drilling in this project started in the Minami-Senbongi district of Shimabara on November 25. Cores down to the depth of about one hundred meters (sand and gravel) were collected in a very high recovery by this day. The first flank drilling will reach the goal of 750 m-depth on early-March. All coring and several measurements using the hole are scheduled. Descriptive images of cores will come soon in the site of GSJ (linked from this HP). Ceremonies for start drilling were held in the drilling site by GSJ, STA and Geo-E (drilling company) on December 6. An open house for the public is scheduled in the drilling site on February 26.

Photos on the drilling site and cores

Photo of Shimbara

November 13, 1999

The extended meeting of the second research group was held in Shimabara during 8-10 November 1999. Ulrich Harms and Thomas Wohrl of GFZ and John Eichelberger of University of Alaska, Fairbanks, joined the meeting. Scientific targets of the conduit drilling, blue print of the drilling, the difficulties were discussed. On the second day, they climbed the summit area of Unzen Volcano, and examined the drilling site. They enjoyed much red leaves on the volcano and bathing in hot spring of Unzen after climbing. The second group will submit the second preliminary proposal to the ICDP, in which the technical workshop of the high temperature volcanic body at Unzen in next summer or autumn is proposed.

October 26, 1999

Four executive members of USDP (Kozo Uto, Hiroshi Shinohara, Yuji Ikeda and Setsuya Nakada) visited Potsdum (GFZ) during 18 and 19 October 1999, in order to introduce the present state of USDP to GFZ, learn the scientific drilling knowledge, and discuss the possibility of its international cooperation with GFZ. They continued the discussion on logging system in the KTB site at Windischeschenbach on 20 and 21 October. They visited also the laboratory of Dr. Don Dingwell of Universitaet Bayreuth.

20 September 1999

The first meeting of the Research Promotion Committee of this project in Tokyo. The schedule of this project, final selection of drilling sites in the first phase (flank drilling), methods of making sample archive, the principle of sample partitioning, and the relationship of this project with ICDP and foreign scientists were discussed.

7 September 1999

The 1st Unzen Scientific Drilling Symposium was held at GSJ, Tsukuba, during September 5-7, 1999. Thirty four talks, related to the planning of this drilling project, scientific and technological results of the F/S research, and future research plans, were presented in the meeting. Sixty seven Japanese scientists were in attendance. On the evening of September 5 they enjoyed talking with "Sushi" and beer in the meeting hall. The second symposium is scheduled as a special session in the Western Pacific Geophysical Meeting (WPGM) held in Tokyo during July 27-30, 2000; tentative title of the session; "Under the volcano: Insights from drilling and surface observations" with co-conveners, S. Nakada, K. Uto, J. Eichelberger, and H. Shimizu.

The joint meeting of 1st and 2nd research groups was held in the same place on the evening of 6 September, discussing selection of the site for the flank drilling in the end of this year, and near future plans. The 3rd meeting of the 2nd research group is scheduled in the early-November at Shimabara, inviting John Eichelberger and a GFZ scientist or engineer.

12 July 1999

The local internet mailing list (udp) started, assisted by Geological Survey of Japan (I. Miyagi). The list involves mostly Japanese scientists who are interested in the Unzen Scientific Drilling Project. Communication is done in Japanese. Announcement of "First Symposium on Unzen Scientific Drilling (in Tsukuba, 5-7 September 1999)" was distributed.

30 June 1999

Official meeting to explain the project to local government people at Obama Town (Unzen), Nagasaki. T. Hirano (STA person in charge of this project), K. Uto (leader), H. Shimizu, S. Nakada (researchers), and S. Sakuma (Drilling Engineer) explained the details of the drilling project and the scientific purposes, referring to safety of the drilling and benefits for the local people. Thirty-three people, including four members of massmedia, were in attendance. The meeting was reported in local newspapers. Managers of the Unzen National Park both of the Environment Agency and of Nagasaki Prefecture aslo took part in this meeting. They discussed the blueprint of the conduit drilling.

11 May 1999

Meeting of 2nd Research Group at GSJ (Tsukuba), discussing the future plan of the conduit drilling and schedule of this group.

8 May 1999

Special Issue on Unzen eruption was published from Elsevier.

Edited by S. Nakada, J.C. Eichelberger, and H. Shimizu; "Unzen Eruption: Magma ascent and dome growth", Jounral of Volcanology and Geothermal Research, volume 89, nos. 1-4, 315p.