三ツ口 丈裕 ：神戸大学・理学部・化学科卒，名古屋大学大学院・理学研究科・大気水圏科学専攻・博士課程前期/後期課程修了・博士（理学）

Takehiro MITSUGUCHI, Ph.D.

Born in 1967 in Aichi, JAPAN

Nationality: Japan


Academic History

Apr 1987-Oct 1991: Faculty of Science, Kobe University, Japan. Awarded the degree of B.Sc. in chemistry.

Nov 1991-Mar 1993: Faculty of Science, Kyoto University, Japan. Research student for geology and mineralogy.

Apr 1993-Mar 1995: Graduate School of Science, Nagoya University, Japan. Awarded the degree of M.Sc. in hydrospheric-atmospheric sciences.

Apr 1995-Feb 2000: Graduate School of Science, Nagoya University, Japan. Awarded the degree of Ph.D. for a thesis entitled “Reconstruction of palaeoceanic environment from multi-element analysis of annually-banded coral skeletons.”


Research Employment History

Apr 1998-Mar 2001: Research fellow of JSPS (Japan Society for the Promotion of Science), working at Department of Earth and Environmental Sciences, Graduate School of Environmental Studies, Nagoya University, Japan

Jan 2002-Dec 2004: Research fellow of JST (Japan Science and Technology Agency) and JSPS, working at Environmental Chemistry Division, NIES (National Institute for Environmental Studies), Tsukuba, Japan

Jan 2005-Mar 2005: Post-doctoral fellow of NIES (National Institute for Environmental Studies), Tsukuba, Japan

Oct 2012-March 2013: Research fellow of Kochi University, Usa Marine Biological Institute, Tosa, Japan

Jan 2014-Mar 2015: Research technician of NIES (National Institute for Environmental Studies), Tsukuba, Japan

Apr 2016-Mar 2018: Special Topic Researcher of Tono Geoscience Center, Japan Atomic Energy Agency, Toki, Japan

Aug 2018-Mar 2021: Special Topic Researcher of Tono Geoscience Center, Japan Atomic Energy Agency, Toki, Japan

Nov 2021-Present: Special Topic Researcher of Tono Geoscience Center, Japan Atomic Energy Agency, Toki, Japan


Membership in Professional Societies/Projects


Publications

(1) Mitsuguchi T., Matsumoto E., Abe O., Uchida T., Isdale P. J. (1996) Mg/Ca thermometry in coral skeletons. Science, v. 274, p. 961-963.

(2) Mitsuguchi T., Matsumoto E., Abe O., Uchida T., Isdale P. J. (1997) Magnesium/calcium ratio of coral skeletons as a palaeothermometer. Proceedings of the 8th International Coral Reef Symposium in Panama, v. 2, p. 1701-1706.

(3) Mitsuguchi T., Matsumoto E., Uchida T., Kawana T., Isdale P. J. (1998) An attempt to recover middle Holocene sea surface temperature in Okinawa region from coral Mg/Ca and Sr/Ca ratios. Proceedings of the 3rd International Marine Science Symposium in Tokyo, p. 50-56.

(4) Mitsuguchi T., Uchida T., Matsumoto E., Isdale P. J., Kawana T. (2001) Variations in Mg/Ca, Na/Ca, and Sr/Ca ratios of coral skeletons with chemical treatments: Implications for carbonate geochemistry. Geochimica et Cosmochimica Acta, v. 65, p. 2865-2874.

(5) Mitsuguchi T., Matsumoto E., Uchida T. (2003) Mg/Ca and Sr/Ca ratios of Porites coral skeleton: Evaluation of the effect of skeletal growth rate. Coral Reefs, v. 22, p. 381-388.

(6) Dang P. X., Mitsuguchi T., Kitagawa H., Shibata Y., Kobayashi T. (2004) Marine reservoir correction in the south of Vietnam estimated from an annually-banded coral. Radiocarbon, v. 46, p. 657-660.

(7) Mitsuguchi T., Kitagawa H., Matsumoto E., Shibata Y., Yoneda M., Kobayashi T., Uchida T., Ahagon N. (2004) High-resolution 14C analyses of annually-banded coral skeletons from Ishigaki Island, Japan: implications for oceanography. Nuclear Instruments and Methods in Physics Research B, v. 223-224, p. 455-459.

(8) Mitsuguchi T. (2004) Study of ocean environment by 14C analysis of annually-banded coral skeletons. (Review paper in Japanese with English title/abstract) Chikyukagaku (Geochemistry), v. 38, p. 287-301.

(9) Dang P. X., Mitsuguchi T., Kitagawa H., Uchida T., Shibata Y. (2006) Sr/Ca ratio of Porites coral from Con Dao Island, South of Vietnam. Proceedings of the 10th International Coral Reef Symposium in Okinawa, p. 567-571.

(10) Mitsuguchi T., Dang P. X., Kitagawa H., Yoneda M., Shibata Y. (2007) Tropical South China Sea surface 14C record in an annually-banded coral. Radiocarbon, v. 49, p. 905-914.

(11) Mitsuguchi T., Dang P. X., Kitagawa H., Uchida T., Shibata Y. (2008) Coral Sr/Ca and Mg/Ca records in Con Dao Island off the Mekong Delta: Assessment of their potential for monitoring ENSO and East Asian monsoon. Global and Planetary Change, v. 63, p. 341-352.

(12) Mitsuguchi T., Uchida T., Matsumoto E. (2010) Na/Ca variability in coral skeletons. Geochemical Journal, v. 44, p. 261-273.

(13) Mitsuguchi T., Kawakami T. (2012) Potassium and other minor elements in Porites corals: implications for skeletal geochemistry and paleoenvironmental reconstruction. Coral Reefs, v. 31, p. 671-681.

(14) Sirianansakul W., Pumijumnong N., Mitsuguchi T., Putchakarn S., Boontanon N. (2012) Mg/Ca and Sr/Ca ratios in a coral from Koh Chueak, Surat Thani, Thailand. Galaxea v. 14, p. 63-72.

(15) Matsumoto T., Maruoka T., Shimoda G., Obata H., Kagi H., Suzuki K., Yamamoto K., Mitsuguchi T., Hagino K., Tomioka T., Sambandam C., Brummer D., Klaus P. M., Aggarwal P. (2013) Tritium in Japanese precipitation following the March 2011 Fukushima Daiichi Nuclear Plant accident. Science of the Total Environment, v. 445-446, p. 365-370.

(16) Mitsuguchi T. (2013) Evaluation of the effects of microscale chemical and isotopic heterogeneity of coral skeleton on conventional Sr/Ca and δ18O paleothermometers. Journal of Earth System Science, v. 122, p. 1335-1340.

(17) Mitsuguchi T., Hirota M., Paleo Labo AMS Dating Group, Yamazaki A., Watanabe T., Yamano H. (2016) Post-bomb coral Δ14C record from Iki Island, Japan: possible evidence of oceanographic conditions on the northern East China Sea shelf. Geo-Marine Letters, v. 36, DOI: 10.1007/s00367-016-0456-4.

(18) Yokoyama T., Kimura J.-I., Mitsuguchi T., Danhara T., Hirata T., Sakata S., Iwano H., Maruyama S., Chang Q., Miyazaki T., Murakami H., Saito-Kokubu Y. (2018) U-Pb dating of calcite using LA-ICP-MS: Instrumental setup for non-matrix-matched age dating and determination of analytical areas using elemental imaging. Geochemical Journal, v. 52, doi:10.2343/geochemj.2.0541.

(19) Saito-Kokubu Y., Mitsuguchi T., Watanabe T., Yamada T., Asami R., Iryu Y. (2019) Preliminary test of the EA-AGE3 system for 14C measurement of CaCO3 samples and coral-based estimation of marine reservoir correction in the Ogasawara Islands, northwestern subtropical Pacific. Radiocarbon, v.61, p. 1593-1601.

(20) Mitsuguchi T., Okabe N., Yokoyama Y., Yoneda M., Shibata Y., Fujita N., Watanabe T., Saito-Kokubu Y. (2021) 129I/127I and Δ14C records in a modern coral from Rowley Shoals off northwestern Australia reflect the 20th-century human nuclear activities and ocean/atmosphere circulations. Journal of Environmental Radioactivity, v.236 Open Access.

(21) Mitsuguchi T., Minakata K., Sugihara K., Hiraoka M., Yoshida M., Saito-Kokubu Y. (2022) Mineral phase analysis of various marine-species shells and skeletons collected in Japan: Implications for marine biominerals. bioRxiv, 2022.11.01. Manuscript rejected by Zoological Science

(22) Mitsuguchi T., Okabe N., Saito-Kokubu Y., Matsuzaki H. (2024) A review and interpretation of iodine-129 in Earth's surface layers: Towards evaluating the long-term stability of geological environments. (Review paper in Japanese with English title/abstract/figure-captions) Journal of Nuclear Fuel Cycle and Environment (Genshiryoku-Backend Kenkyu), v. 31, p. 96-110 (Open Access).


Open Data Library

(1) Coral Mg/Ca, Sr/Ca and δ18O data (Porites lutea, 1986-1993 AD, Ishigaki Island, Japan) of Mitsuguchi et al. (1996).

(2) Coral Mg/Ca, Sr/Ca and δ18O data (Porites lutea, 1980-1993 AD, Ishigaki Island, Japan) of Mitsuguchi et al. (1997).

(3) Coral Mg/Ca and Sr/Ca data (Porites australiensis, 1992-1994 AD, Ishigaki Island, Japan) of Mitsuguchi et al. (2003).

(4) Coral Δ14C data (Porites lutea, 1985-1993 AD, Ishigaki Island, Japan) of Mitsuguchi et al. (2004).

(5) Coral Δ14C data (Porites sp., 1948-1999 AD, Con Dao Island, Vietnam) of Mitsuguchi et al. (2007).


Papers in preparation or under review

(1) Seasonal Ba/Ca variation of coral skeleton off the Mekong Delta and its possible controlling factors

(2) Seasonal fluctuation of coral skeletal Ba/Ca ratio in Ryukyu Islands, Japan


Ph.D. dissertation at Nagoya University, Japan, earned on 29 February 2000

Mitsuguchi T. (2000) Reconstruction of palaeoceanic environment from multi-element analysis of annually-banded coral skeletons. 91 pp.


Presentations in international conferences and workshops

(1) Mitsuguchi T., Matsumoto E., Abe O., Uchida T., Isdale P. J.: Magnesium/calcium ratio of coral skeleton as a palaeothermometer. The 8th International Coral Reef Symposium in Panama, 24-29 June 1996.

(2) Mitsuguchi T., Matsumoto E., Uchida T., Kawana T., Isdale P. J.: Reconstructions of sea surface temperatures during middle Holocene in Okinawa region by applying coral Mg/Ca and Sr/Ca thermometers. International Symposium on Quaternary Environmental Change in Asia and Western Pacific Region in University of Tokyo, Japan, 14-17 October 1997.

(3) Mitsuguchi T., Matsumoto E., Abe O., Uchida T., Uchida H., Kawana T., Isdale P. J.: A multi-tracer approach to modern and fossil coral records. The 1st IGBP-PAGES Open Science Meeting in University of London, UK, 20-23 April 1998.

(4) Mitsuguchi T., Matsumoto E., Uchida T., Isdale P. J., Kawana T., Kan H.: Early Holocene sea surface temperature in the Ryukyus retrieved from coral Mg/Ca and Sr/Ca ratios. International Workshop on Pacific Coral Records in Nagoya University, Japan, 7-9 February 2001.

(5) Mitsuguchi T., Kitagawa H., Matsumoto E., Shibata Y., Isdale P. J.: High-resolution 14C analysis of annually-banded coral skeletons from Ishigaki Island, Japan. The 9th International Conference on Accelerator Mass Spectrometry (AMS-9) in Nagoya University, Japan, 9-13 September 2002.

(6) Mitsuguchi T., Matsumoto E., Uchida T., Isdale P. J., Kawana T., Kan H.: Early mid-Holocene sea-surface temperature in the Ryukyu Islands reconstructed from coral Mg/Ca and Sr/Ca ratios. The 10th International Coral Reef Symposium in Okinawa, Japan, 28 June-2 July 2004.

(7) Mitsuguchi T., Dang P. X., Kitagawa H., Shibata Y.: Seawater 14C time series of AD 1948-1999 in the tropical South China Sea: Reconstruction from coral annual bands. The 19th International Radiocarbon Conference in Oxford University, UK, 3-7 April 2006.

(8) Mitsuguchi T., Dang P. X., Kitagawa H., Uchida T., Shibata Y.: Coral Sr/Ca and Mg/Ca records from 1948 through 1999 in Con Dao Island, Vietnam: Monitoring of ENSO and East Asian monsoon in the South China Sea. 21st Century COE International Symposium on Climate Change in Tohoku University, Japan, 6-9 November 2006.

(9) Sirianansakul W., Pumijumnong N., Mitsuguchi T., Boontanon N., Putchakarn S.: Accumulation of heavy metals in scleractinian corals at Koh Chueak, Surat Thani Province, Thailand. 37th Congress on Science and Technology of Thailand, Bangkok, Thailand, 10-12 October 2011.

(10) Mitsuguchi T., Okabe N., Miyake M., Matsubara A., Fujita N., Watanabe T., Saito-Kokubu Y.: Preliminary test for 129I measurement of CaCO3 samples in JAEA-AMS-TONO. The 8th East Asia Accelerator Mass Spectrometry Symposium, Nagoya, Japan, 3-6 December 2019.


Presentations in domestic conferences (in Japanese)：国内学会発表（日本語）

(1) 三ツ口 丈裕, 松本 英二, 阿部 理, 内田 哲男, 大橋 和夫（1994）石垣島塊状サンゴの骨格年輪中の金属元素濃度の変動．日本地球化学会　第41回年会　於・名古屋大学.

(2) 三ツ口 丈裕, 松本 英二, 内田 哲男（1995）造礁サンゴ骨格の金属元素による海洋環境復元．日本地球化学会　第42回年会　於・東海大学.

(3) 三ツ口 丈裕, 松本 英二, 内田 哲男（1996）サンゴ骨格のMg/Ca古水温計の問題点に関する考察．日本地球化学会　第43回年会　於・北海道大学.

(4) 三ツ口 丈裕, 松本 英二, 内田 哲男, 河名 俊男（1997）サンゴのMg/Ca・Sr/Ca古水温計を用いた沖縄-完新世の海水温変動の復元．日本地球化学会　第44回年会　於・東京都立大学.

(5) 三ツ口 丈裕, 松本 英二, 阿部 理, 内田 哲男, 河名 俊男, 内田 弘, Peter J. Isdale（1997）サンゴ骨格の微量元素を用いた古海洋環境変動の復元．日本サンゴ礁学会　設立大会　於・琉球大学.

(6) 三ツ口 丈裕, 内田 哲男, 岡本 孝則, 松本 英二, 河名 俊男, Peter J. Isdale（1999）化学的処理によるハマサンゴ骨格試料のMg/Ca比，Na/Ca比，Sr/Ca比の変化（骨格構造中の微量元素分布の不均一性）．日本地球化学会　第46回年会　於・工業技術院筑波研究センター.

(7) 三ツ口 丈裕, 内田 哲男, 松本 英二（2000）サンゴ骨格形成時のMg，Na，SO42-の類似挙動．日本地球化学会　第47回年会　於・山形大学.

(8) 三ツ口 丈裕, 北川 浩之, 松本 英二, 柴田 康行, 米田 穣, 小林 利行（2002）石垣島産現生ハマサンゴ骨格年輪の14C季節変動．日本サンゴ礁学会　第5回大会　於・東京工業大学.

(9) 三ツ口 丈裕, 北川 浩之, 柴田 康行, 米田 穣, 松本 英二, 内田 哲男, 阿波根 直一（2003）石垣島サンゴ骨格年輪中の14C濃度の季節変動：アジアモンスーンとの関わり．第２回サンゴ年輪ワークショップ　於・産業技術総合研究所（つくば）.

(10) 三ツ口 丈裕, 松本 英二, 内田 弘, 内田 哲男, 阿部 理, 阿波根 直一（2003）サンゴ骨格年輪中のBa/Ca比の季節変動と支配要因．第２回サンゴ年輪ワークショップ　於・産業技術総合研究所（つくば）.

(11) 三ツ口 丈裕, 松本 英二, 内田 弘, 内田 哲男, 阿部 理, 阿波根 直一（2003）石垣島現生ハマサンゴ骨格年輪のBa/Ca比の季節変動．日本サンゴ礁学会　第６回大会　於・石垣島.

(12) Dang X. Phong, 三ツ口 丈裕, 北川 浩之, 柴田 康行, 小林 利行（2003）ベトナム南部の海洋リザーバ年代：コンダオ島現生ハマサンゴ骨格年輪の14C分析　日本サンゴ礁学会　第６回大会　於・石垣島.

(13) 三ツ口 丈裕, Dang X. Phong, 北川 浩之, 内田 哲男, 柴田 康行（2004）20世紀後半のベトナム南部の海水温変動：サンゴ骨格年輪のSr/Ca分析による復元　日本地球化学会　第51回年会　於・静岡大学.

(14) 三ツ口 丈裕, Dang X. Phong, 北川 浩之, 内田 哲男, 柴田 康行（2008）メコンデルタ沖・コンダオ島におけるサンゴ年輪のSr/CaおよびMg/Caの記録：ENSOおよび東アジアモンスーンの監視手段としての評価　日本地球化学会　第55回年会　於・東京大学.

(15) 三ツ口 丈裕, Dang X. Phong, 北川 浩之, 内田 哲男, 柴田 康行（2009）南シナ海南部のサンゴ骨格のSr/Ca比に記録されたENSO・東アジアモンスーン遠隔結合　日本地球惑星科学連合　2009年大会　於・幕張メッセ国際会議場.

(16) 三ツ口 丈裕, Dang X. Phong, 北川 浩之, 柴田 康行（2009）メコンデルタ沖のサンゴ骨格に見られるBa/Ca比の季節変動とその要因　日本地球化学会　第56回年会　於・広島大学.

(17) 三ツ口 丈裕, 内田 哲男, 松本 英二（2010）造礁サンゴ骨格のNa/Ca比の変動要因および骨格内でのNaの存在状態　日本地球化学会　第57回年会　於・立正大学 （招待講演）.


Lectures（講義/講演）


News paper articles and others (in Japanese)：新聞記事，その他（日本語）

  • 『サンゴで海水温算出：名大グループ　気候変動予測に貢献』：毎日新聞朝刊，1996年11月19日.
  • 『サンゴ年輪と気候変動』：特許四季報，2004年創刊２号 (218頁コラム).
  • 日本サンゴ礁学会第5回大会受賞：2002年11月1日.

Curriculum Vitae

  • Certificate of master's degree from Nagoya Univ
  • Certificate of doctor's degree from Nagoya Univ
  • Transcript of academic record in the master course of Nagoya Univ
  • Transcript of academic record in the doctor course of Nagoya Univ


Researchers network services

My previous and current research

   To date, my research has been focused on the use of coral skeletons as a tool for investigation of past sea-surface environment and climate. Most corals living in tropical/subtropical shallow ocean waters (< 30 m in depth) secrete aragonite skeletons (i.e., CaCO3) at extension rates of 5-30 mm/yr with various forms in their skeletal growth: massive, branching, leafy, and so on, generally depending on coral species. Massive coral species can grow continuously for hundreds of years to form gigantic dome-shaped colonies (up to several meters in height) Figure 1, and skeletons of the colonies have annual growth bands. The annual growth bands can be observed by cutting a massive coral, along its growth direction, into a several-millimeter-thick slab and then X-raying the skeletal slab or photographing it under long-wavelength UV light (~350 nm). Figure 2 shows an X-ray positive image of a skeletal core sample drilled from a massive coral colony in Ishigaki Island, Japan (i.e., the colony shown in Figure 1: darker and lighter bands correspond to higher and lower skeletal density, respectively, and each pair of the adjacent higher-density and lower-density bands represents an annual growth of the skeleton. For this coral sample, the higher-density and lower-density bands are formed in summer and winter, respectively.

Figure 1. (A) Photo of a 2-m-high massive coral colony (Porites lutea) and me using an underwater video camera in Ishigaki Island, Japan. This photo was taken by Dr. Osamu Abe. In September 1993, a vertical core sample was drilled from the top of this colony in collaboration between Institute for Hydrospheric-Atmospheric Sciences of Nagoya University and the Australian Institute of Marine Science (Dr. Peter J. Isdale and Mr. Bruce Parker). Chemical analyses (Mg/Ca, Sr/Ca and δ18O) of the core sample were published in Science in 1996 (Mitsuguchi et al., 1996). In this publication, we reported that the Mg/Ca ratio was strongly correlated with sea-surface temperature. (B) Map showing the location of Ishigaki Island, Japan.


Figure 2. X-radiograph positive image of a coral skeletal core (Porites lutea: 180 cm in length) collected from Ishigaki Island, Japan (i.e., from the massive coral colony shown in Figure 1) and sliced into a 7-mm-thick slab. This radiograph indicates that the coral core has annual bands of AD 1891-1993: darker and lighter bands correspond to higher and lower skeletal density, respectively. Each pair of the adjacent higher-density and lower-density bands represents skeletal growth over one year: the former and latter are formed in summer and winter, respectively. Minor- and trace-element measurements (Sr/Ca, Mg/Ca, Ba/Ca, Na/Ca and K/Ca) and isotopic analyses (δ18O and Δ14C) for the annual bands of AD 1985-1993 are reported and discussed in Mitsuguchi (2000), Mitsuguchi and Kawakami (2012), and Mitsuguchi et al. (1996, 1997, 2004, 2010).


   Figure 3 shows an X-radiograph (positive image) and an UV-luminescence photo (~352 nm) of a skeletal core sample drilled from a massive coral colony in Con Dao Island, Vietnam. This island is located ~90 km off the Mekong Delta coast (Figure 4). The core drilling was performed, by means of SCUBA diving, by me, Dr. Koichi Watanabe, Dr. Phong X. Dang and staff of the Con Dao National Park (Figure 5). The annual banding in the X-radiograph is due to variation in the skeletal density, while that in the UV-luminescence photo is mainly due to variation in the concentration of humic substances in the skeleton. It can be assumed that the source of the humic substances is the Mekong River.

   Thus, gigantic massive coral colonies can be used as archives that offer multi-century-long continuous observations of tropical/subtropical sea-surface environment and climate. To secrete their CaCO3 skeletons, corals utilize the dissolved inorganic carbon (DIC: HCO3(-), CO3(2-), CO2, and H2CO3) and Ca of ambient seawater. In addition to the DIC and Ca, many other dissolved ions in seawater are incorporated into the skeletons as minor or trace components (e.g., Sr, Mg, U, B, Ba, Na, K, F, SO4(2-), etc). It is well known that some chemical/isotopic components of marine carbonates can be used to reconstruct past physical and/or chemical conditions of seawater from which the carbonates were formed. Such components are often called ‘proxies’ for past marine environmental conditions. For coral skeletons, the Sr/Ca ratio is generally a proxy for seawater temperature, and the δ18O value is a proxy for seawater temperature and/or seawater δ18O value. Relationships of the Sr/Ca and δ18O with temperature have been established in many studies, and these relationships are called the coral Sr/Ca thermometer and δ18O thermometer. Since annual bands of massive coral skeletons are mostly 10-15 mm in width, measurements of the proxies at 1-mm intervals along the skeletal growth direction provide information of past environmental variations at a temporal resolution of about 1 month.

   In my research, a lot of chemical/isotopic components, including 14C, of massive coral skeletons have been measured for modern and fossil samples collected from Japan (Ishigaki Island and Okinawa Island), Australia (the Great Barrier Reef), Vietnam (Con Dao Island), and so on.


Figure 3. X-radiograph positive print (upper) and UV-luminescence photo (lower) of a coral skeletal core slice (Porites sp.) from Con Dao Island, Vietnam, ~90 km from the mouth of the Mekong River (Figure 4). Both pictures show annual bands of AD 1948-1999 in the skeletal core. The annual banding in the X-radiograph is due to variation in the skeletal density, while that in the UV-luminescence photo is mainly due to variation in the concentration of humic substances in the skeleton. It can be assumed that the source of the humic substances is the Mekong River. Along the skeletal growth axes indicated as yellow lines, 627 samples were taken at 1-mm intervals for elemental analyses (Sr/Ca, Mg/Ca, Ba/Ca, etc.). The sampling resolution of 1 mm corresponds to a temporal resolution of ~5 weeks. The Sr/Ca and Mg/Ca data are provided and discussed in Mitsuguchi et al. (2008). The annually-resolved Δ14C data of this coral are provided and discussed in Dang et al. (2004) and Mitsuguchi et al. (2007).

Figure 4. Map of the South China Sea showing the locations of Con Dao Island and the Mekong River.


Figure 5. Photo taken just before boarding a boat for coral drilling in Con Dao Island, Vietnam (Date: 17 May 2000). Dr. Koichi Watanabe and I are the fourth and third from the left. The others are staff of the Con Dao National Park. This photo was taken by Dr. Phong X. Dang of Vietnamese Academy of Science and Technology.


Galapagos Expedition in June 1996

Figure 6. My flight route from Japan to Galapagos Islands in June 1996


Figure 7. A TAME airplane (the Flagship Airline of Ecuador) before departure from the old Mariscal Sucre International Airport (2813 m AMSL) in Quito to Galapagos Islands (the Seymour Galapagos Ecological Airport: 63 m AMSL) in June 1996


Figure 8. Galapagos tour members in Santa Cruz Island in June 1996


Figure 9. Visiting Charles Darwin Research Station in Puerto Ayora, Santa Cruz Island in June 1996


Figure 10. Floods in the floodplain of the Chi River, Thailand (a tributary of the Mekong River), 8th October 2011.

My hobby was astronomy and telescope making when I was a high school student...

Figure 10. Photo of the last apparition of Halley's Comet in March 1986, when it was seen around the boundary between Centaurus and Lupus. This photo was taken at Cape Irago, Japan, using a Nikon FE camera with a NIKKOR 50mm F1.4 lens.