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The Manila galleon San Francisco sank off the coast of Japan in 1609 after almost two months of sailing through storms and hurricanes that damaged the ship to the point that it was carrying more than two metres of water in its hold. This article provides an account of the final journey of San Francisco according to primary and secondary sources. It also proposes a set of theoretical dimensions for the galleon based on its tonnage, contemporary vessels of similar tonnages, hull ratios provided in late sixteenth- and early seventeenth-century shipbuilding treatises and ordinances, and archaeological parallels. In addition, the authors estimate possible distances from the wreck of the galleon to the shore, using the distances provided in accounts of wreck and contemporary marine leagues, and the theoretical draft of the vessel.

The Ganymede laser-altimeter (GALA) is one of 10 instruments on ESA’s Jupiter Icy Moons Explorer (JUICE) mission. The scientific goals cover a wide range from geology, geophysics to geodesy of the icy moons Ganymede, Europa and Callisto. JUICE will explore Jupiter, its magnetosphere and satellites first in orbit around Jupiter before going finally into polar orbit around Ganymede. GALA is developed under responsibility of the DLR Institute of Planetary Research in collaboration with industry and institutes from Germany, Japan, Switzerland and Spain. GALA has two main objectives: (1) providing Ganymede’s topography from global to local scales (2) determination of Ganymede's tidal variations of surface elevations. GALA is a single-beam laseraltimeter: a laser pulse (1064 nm) is emitted by using a Nd:YAG laser firing at 30 Hz (nominal). After about 3 msec (500 km altitude) the reflection of the pulse from the surface of Ganymede is received by a telescope and transferred to the detector (Avalanche Photo Diode). The signal is digitized and transferred to the range finder module, which determines (a) time of flight (b) pulse shape, and (c) energy of the received pulse. Including information on the spacecraft position and attitude the height of the terrain above a reference surface is determined for each shot from time-of-flight measurements. The GALA flight model was delivered to ESA in August 2021. After several tests on instrument level the integration on the JUICE spacecraft started in September 2021 and first tests were performed successfully in October 2021. With the launch scheduled for 2023, GALA will go through several tests, among them an end-to-end test including laser-receiver measurements. Here we present the instrument's current status with respect hardware integration and regarding the verification of its performance.

Full list of authors: Enya, Keigo; Kobayashi, Masanori; Kimura, Jun; Araki, Hiroshi; Namiki, Noriyuki; Noda, Hirotomo; Kashima, Shingo; Oshigami, Shoko; Ishibashi, Ko; Yamawaki, T.; Tohara, Kazuyuki; Saito, Yoshifumi; Ozaki, Masanobu; Mizuno, Takahide; Kamata, Shunichi; Matsumoto, Koji; Sasaki, Sho; Kuramoto, Kiyoshi; Sato, Yuki; Yokozawa, Takeshi; Numata, Tsutomu; Mizumoto, Satoko; Mizuno, Hiroyuki; Nagamine, Kenta; Sawamura, Akihiko; Tanimoto, Kazuo; Imai, Hisato; Nakagawa, Hiroyuki; Kirino, Okiharu; Green, David; Fujii, Masayuki; Iwamura, Satoru; Fujishiro, Naofumi; Matsumoto, Yoshiaki; Lingenauber, Kay; Kallenbach, Reinald; Althaus, Christian; Behnke, Thomas; Binger, Jan; Daurskikh, Anna; Eisenmenger, Henri; Heer, Ulrich; Hüttig, Christian; Lara, Luisa M.; Lichopoj, Alexander; Lötzke, Horst-Georg; Lüdicke, Fabian; Michaelis, Harald; Pablo Rodriguez Garcia, Juan; Rösner, Kerstin; Stark, Alexander; Steinbrügge, Gregor; Thabaut, Pascal; Thomas, Nicolas; del Togno, Simone; Wahl, Daniel; Wendler, Belinda; Wickhusen, Kai; Willner, Konrad; Hussmann, Hauke.--This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/ by-nc-nd/4.0/)., The Jupiter Icy Moons Explorer (JUICE) is a science mission led by the European Space Agency, being developed for launch in 2023. The Ganymede Laser Altimeter (GALA) is an instrument onboard JUICE, whose main scientific goals are to understand ice tectonics based on topographic data, the subsurface structure by measuring tidal response, and small-scale roughness and albedo of the surface. In addition, from the perspective of astrobiology, it is imperative to study the subsurface ocean scientifically. The development of GALA has proceeded through an international collaboration between Germany (the lead), Japan, Switzerland, and Spain. Within this framework, the Japanese team (GALA-J) is responsible for developing three receiver modules: the Backend Optics (BEO), the Focal Plane Assembly (FPA), and the Analog Electronics Module (AEM). Like the German team, GALA-J also developed software to simulate the performance of the entire GALA system (performance model). In July 2020, the Proto-Flight Models of BEO, FPA, and AEM were delivered from Japan to Germany. This paper presents an overview of JUICE/GALA and its scientific objectives and describes the instrumentation, mainly focusing on Japan's contribution. © 2021 COSPAR., NSO/Kitt Peak data (synoptic maps of He I Å intensity) used here are produced cooperatively by NSF/NOAO, NASA/GSFC, and NOAA/SEL. Sunspot number (version 2) comes from the Sunspot Index and Long-term Solar Observations at Royal Observatory of Belgium, Brussels. All used data are courtesy to be downloaded from their web sites. The authors would like to express their deep thanks to the staffs of these web sites. This work is supported by the National Natural Science Foundation of China (11973085, 11903077, 11803086, and 11633008), the Yunnan Ten-Thousand Talents Plan (the Yunling-Scholar Project), the national project for large scale scientific facilities (2019YFA0405001), and the Chinese Academy of Sciences., With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.

Many icy Solar System bodies possess subsurface oceans. On Pluto, Sputnik Planitia's location near the equator suggests the presence of a subsurface ocean and a locally thinned ice shell. To maintain an ocean, Pluto needs to retain heat inside. On the other hand, to maintain large variations in its thickness, Pluto's ice shell needs to be cold. Here we show, by thermal evolution and viscous relaxation calculations, that the presence of a thin layer of clathrate hydrates (gas hydrates) at the base of the ice shell can explain both the long-term survival of the ocean and the maintenance of shell thickness contrasts. Clathrate hydrates act as a thermal insulator, preventing the ocean from completely freezing while keeping the ice shell cold and immobile. The most likely clathrate guest gas is methane, derived from precursor bodies and/or cracking of organic materials in the hot rocky core. Nitrogen molecules initially contained and/or produced later in the core would probably not be trapped as clathrate hydrates, instead supplying the nitrogen-rich surface and atmosphere. The formation of a thin clathrate hydrate layer cap to a subsurface ocean may be an important generic mechanism to maintain long-lived subsurface oceans in relatively large but minimally heated icy satellites and Kuiper belt objects.

Many icy solar system bodies possess subsurface oceans. At Pluto, Sputnik Planitia’s location near the equator suggests the presence of a subsurface ocean and a locally thinned ice shell. To maintain an ocean, Pluto needs to retain heat inside. On the other hand, to maintain large variations in ice shell thickness, Pluto’s ice shell needs to be cold. Achieving such an interior structure is problematic. Here we show that the presence of a thin layer of clathrate hydrates (gas hydrates) at the base of the ice shell can explain both the long-term survival of the ocean and the maintenance of shell thickness contrasts. Clathrate hydrates act as a thermal insulator, preventing the ocean from complete freezing while keeping the ice shell cold and immobile. The most likely clathrate guest gas is methane either contained in precursor bodies and/or produced by cracking of organic materials in the hot rocky core. Nitrogen molecules initially contained and/or produced later in the core would likely not be trapped as clathrate hydrates, instead supplying the nitrogen-rich surface and atmosphere. The formation of a thin clathrate hydrate layer capping a subsurface ocean may be an important generic mechanism maintaining long-lived subsurface oceans in relatively large but minimally-heated icy satellites and Kuiper Belt Objects.

The Chau Tan shipwreck, probably the earliest shipwreck in Vietnam, was found in the waters off the shore of Binh Son District in Quang Ngai Province in the early 2000s. Dr. Nishimura initiated a study of the shipwreck material, but it was cut short by his sudden demise. A group of Japanese scholars continued the project in co-operation with the Institute of Archaeology (Vietnam). Since remnants of the shipwreck were pillaged and their archaeological contexts were not recorded, this initial study is limited to a comparative assessment of the recovered items, including wooden timbers from the hull and Chinese ceramics. It is also a case study for addressing the ethical issues of raising shipwreck remains in Vietnam for commercial purposes without conducting scientific surveys. The study indicates that the ship timbers came from an eighth-ninth century Southeast Asian ship, and that the Chinese ceramics can be assigned to the Tang Dynasty. A number of inked or inscribed characters on ceramic shards indicate the involvement of Indian Ocean merchants.

The eruptive histories of Ulleungdo (South Korea) and Changbaishan (North Korea/China border) volcanoes are not well constrained since their proximal stratigraphies are poorly exposed or largely inaccessible. However, determining the past behaviour of these volcanoes is critical since future eruptions are likely to disperse ash over some of the world’s largest metropolitan regions. Alkaline tephra deposits erupted from both centres are routinely identified in marine cores extracted from the Sea of Japan, as well as high-resolution lacustrine records east of the volcanoes. Here, we review the distal ash occurrences derived from Ulleungdo and Changbaishan and provide new data from the Lake Suigetsu (central Honshu, Japan) sediment core, in order to provide a more complete and constrained eruption framework. The intensely-dated Lake Suigetsu archive provides one of the most comprehensive distal eruption records for both centres, despite being located ca. 500 km E of Ulleungdo and ca. 1000 km SSE of Changbaishan. The Suigetsu record is utilised to precisely date and geochemically fingerprint (using major, minor and trace element glass compositions) ash fall events that reached central Honshu. Here, we identify a new non-visible (cryptotephra) layer in the Suigetsu sediments, which reveals a previously unreported explosive event from Changbaishan at 42,750 – 42,323 IntCal13 yrs BP (95.4 % confidence interval). This event is chronologically and geochemically distinct from the B-J (Baegdusan-Japan Basin) tephra reported in the Sea of Japan (ca. 50 ka). Furthermore, we also confirm that the widespread U-Ym tephra erupted from Ulleungdo reached central Japan, and is herein dated to 40,332 – 39,816 IntCal13 yrs BP (95.4 % confidence interval). This terrestrial 14C-derived age of the U-Ym can be used to constrain the chronology of marine records containing the same marker layer. This reviewed and integrated tephrostratigraphic framework highlights the pivotal role that distal sedimentary records can play in evaluating the eruptive histories and hazard potential of Ulleungdo and Changbaishan.

The eruptive histories of Ulleungdo (South Korea) and Changbaishan (North Korea/China border) volcanoes are not\ud well constrained since their proximal stratigraphies are poorly exposed or largely inaccessible. However, determining\ud the past behaviour of these volcanoes is critical since future eruptions are likely to disperse ash over some of the\ud world’s largest metropolitan regions. Alkaline tephra deposits erupted from both centres are routinely identified in\ud marine cores extracted from the Sea of Japan, as well as high-resolution lacustrine records east of the volcanoes.\ud Here, we review the distal ash occurrences derived from Ulleungdo and Changbaishan and provide new data from the\ud Lake Suigetsu (central Honshu, Japan) sediment core, in order to provide a more complete and constrained eruption\ud framework. The intensely-dated Lake Suigetsu archive provides one of the most comprehensive distal eruption\ud records for both centres, despite being located ca. 500 km E of Ulleungdo and ca. 1000 km SSE of Changbaishan.\ud The Suigetsu record is utilised to precisely date and geochemically fingerprint (using major, minor and trace element\ud glass compositions) ash fall events that reached central Honshu. Here, we identify a new non-visible (cryptotephra)\ud layer in the Suigetsu sediments, which reveals a previously unreported explosive event from Changbaishan at 42,750\ud – 42,323 IntCal13 yrs BP (95.4 % confidence interval). This event is chronologically and geochemically distinct from\ud the B-J (Baegdusan-Japan Basin) tephra reported in the Sea of Japan (ca. 50 ka). Furthermore, we also confirm that\ud the widespread U-Ym tephra erupted from Ulleungdo reached central Japan, and is herein dated to 40,332 – 39,816\ud IntCal13 yrs BP (95.4 % confidence interval). This terrestrial 14C-derived age of the U-Ym can be used to constrain\ud the chronology of marine records containing the same marker layer. This reviewed and integrated tephrostratigraphic\ud framework highlights the pivotal role that distal sedimentary records can play in evaluating the eruptive histories and\ud hazard potential of Ulleungdo and Changbaishan.

金沢大学理工研究域地球社会基盤学系, An amendment to this paper has been published and can be accessed via a link at the top of the paper. © 2020, The Author(s).

International audience; We propose the extensively studied Chiba section of the Chiba composite section (CbCS) as the Global Boundary Stratotype Section and Point (GSSP) to define the base of the Middle Pleistocene Subseries and Chibanian Stage. The CbCS is a continuous and expanded marine sedimentary succession within the middle of the Ko-kumoto Formation, Boso Peninsula, Chiba Prefecture. It contains well-preserved pollen, marine micro-and macrofossils, a tightly-defined Matuyama-Brunhes (M-B) paleomagnetic polarity boundary, and numerous tephra beds, allowing the establishment of a robust and precise chronostratigraphic framework across the Lower-Middle Pleistocene boundary. Its deep-marine, open-ocean continental slope setting, coupled with high sedimentation rates with no evidence of abrupt deposition, has resulted in preserving both terrestrial and marine environmental changes in and around Marine Isotope Stage (MIS). We have performed high-resolution oxygen isotope analysis , as well as detailed sedimentological, geochemical, and biostrati-graphic studies of the CbCS, confirming the completeness of the stratigraphic interval spanning the Lower-Middle Pleistocene boundary. The M-B polarity boundary serves as the agreed primary guide for the Lower-Middle Pleistocene boundary, and the CbCS represents one of the most detailed marine sedimentary records yet obtained for this reversal, yielding an astronomical age of. ka with a duration of ca.. kyr. This section therefore offers an exceptional opportunity to calibrate the geological time scale as well as understand the dynamics of the geodynamo. The widespread Byk-E tephra lies close to the reversal, allowing precise regional lithostrati-graphic correlation. The CbCS is easy to access from international airports. The section will be permanently preserved and maintained by the local government as a natural monument. Based on these attributes , the base of the Byk-E tephra bed in the Chiba section is the best horizon for establishing the GSSP that will define the Lower-Middle Pleistocene boundary.

Background Multifocal motor neuropathy (MMN) almost purely involves motor nerve. About 20% MMN patients develop minor sensory symptoms in the course of disease. Material and method We reported a 62-year-old male who developed a slowly progressive asymmetrical limb weakness for five years. Motor nerve conduction studies showed definite CB in left median and ulnar nerves, and probable CB in right tibial nerve. Although the patient complained of no sensory symptom, sensory never conduction studies showed absent sensory nerve action potential (SNAP) for bilateral medial plantar and fibular nerves, left sural nerve and reduced amplitude for left median, ulnar and radial nerves. Conduction velocities were otherwise normal. One month after receiving intravenous immunoglobulin (IVIg), his weakness alleviated apparently. A substantial increase in motor amplitude recorded with stimulation at the PF indicated a partial reversal of CB. The SNAP amplitude of left median, ulnar and radial nerves increased more than 50% and the return of bilateral fibular nerve potentials provided evidence of reversible conduction failure in sensory nerves. We reviewed related literature for this performance. Result Three previously published studies reported such a decrease of SNAP amplitude in MMN patients. Such features suggest a more prominent axonal damage more than demyelination. The hyperpolarization of axolemma, resulting from axonal Na+/K+ pump inhibition at the lesion site and overactivity at the adjacent site may constitutes the prominent mechanism of CB. Conclusion Amplitude reduction of SNAP combined with motor CB, which recovered rapidly after IVIg, may suggest axonal damage rather than demyelination.

第18回宇宙科学シンポジウム (2018年1月9日-10日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, 18th Space Science Symposium (January 9-10, 2018. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)Sagamihara Campus), Sagamihara, Kanagawa Japan, 資料番号: SA6000118144, レポート番号: P-111

Background The presence of sensory nerve conduction block is not routinely assessed in the evaluation of patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Whether this can be useful is not well known. Methods We respectively analyze the serial sensory conduction studies of 20 patients with the diagnosis of typical CIDP. Sensory nerve action potential (SNAP) amplitudes and sensory conduction velocities were recorded in the median, ulnar, tibial, peroneal and sural nerves. Follow-up studies were compared with the baseline to evaluate the variation of SNAP amplitudes in serial recordings. Results Four patients were excluded because of clinical aggravation, and the data of sixteen patients were analyzed, including serial sensory conduction studies in 136 nerves. The SNAPs in 82 nerves were absent at baseline, of which the SNAPs in 24 nerves reappeared during follow-up studies, with a mean amplitude of 3.23 ± 3.57 μ V. In the other 54 nerves, 36/54 (66.7%) SNAP amplitudes increased (median increased by 45%) compared to the baseline, and the improvement rates in 15 nerves were greater than 50%. The mean increase in median nerve was the highest (r = 56.64%), followed by tibial nerve (r = 46%), sural nerve (r = 38.75%), ulnar nerve (r = 28.4%), and peroneal nerve (r = 15.75%). Notably, 20/29 (68%) initially normal sensory nerves showed significant increase in SNAP amplitude (median increased by 37.5%), and the improvement rates in 6 nerves were greater than 50%. Conclusions We propose that conduction block may also exist in sensory nerves, segmental sensory conduction and follow-up studies may be of great value in evaluating patients with CIDP.

第17回宇宙科学シンポジウム (2017年1月5日-6日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, 17th Space Science Symposium (January 5-6, 2017. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)Sagamihara Campus), Sagamihara, Kanagawa Japan, 著者人数: 33名, 資料番号: SA6000060090, レポート番号: P-048

第17回宇宙科学シンポジウム (2017年1月5日-6日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, 17th Space Science Symposium (January 5-6, 2017. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)Sagamihara Campus), Sagamihara, Kanagawa Japan, 著者人数: 14名, 資料番号: SA6000060024, レポート番号: S4-009

著者人数: 12名, Accepted: 2012-07-31, 資料番号: SA1004475000

著者人数：18名, Accepted: 2010-12-10, 資料番号: SA1002679000

著者人数：12名, Accepted: 2010-02-22, 資料番号: SA1002681000

資料番号: AC1000057000

The highly sensitive urine glucose meter based on amperometric glucose sensor was developed and commercialized. It shows remarkable performances of wide measurement range in 0–2000 mg dl−1, rapid response time as 6 s and robustness against influence by interferents like ascorbic acid or acetaminophen. Correlation between the developed urine glucose meter and commercialized clinical-use urine glucose analyzer showed excellent linear relationship. The monitoring of postmeal blood glucose levels by assess of urine glucose of actual subjects was performed with the developed urine glucose meter. The experimental results suggest the urine glucose level 120 min following the meal should be the appropriate index for diabetes or impaired glucose tolerance to control blood glucose level. The new portable meter was developed, and is expected for flexible use at places other than home or office.

第30回太陽系科学シンポジウム(2008年12月18日-19日, 宇宙航空研究開発機構宇宙科学研究本部), 形態: カラー図版あり, 資料番号: AA0064290021

3章 惑星における氷の物質と化学, 太陽系の外惑星領域にある衛星は，そのほとんどがH2O主体の氷で覆われた"氷衛星"である．これらは数の多さや多様なサイズを持つが，最も注目すべき点は大規模な地質活動の跡が見られることである．地球の月とは異なるその外見は，氷衛星を覆う氷の存在とその特徴的な物性が作り出している と思われる．本稿では代表例として木星の衛星エウロパに見られる地溝帯と土星の衛星エンセラダスで発見された氷噴出現象に着目し，これらの現象の原因を探る．そこには，液体水が固化する際に体積が増加するという氷特有の物性が大きく関わっている可能性がある．, Most eminent feature of tectonic activity on the icy satellites is extensional signatures, which have been formed by tensional stress. The example is narrow ridges and bandshaped terrain on Europa, and parallel, periodically spaced fractures called by Tiger Stripes on Enceladus. These features suggest a possibility that the surface have been fractured and extended due to tensional stress. We have focused on the solidification of the liquid water and the accompanying volume change as one of the dominant sources for such stresses. To estimate the stress state in the solid ice region surrounding the water region, we first performed numerical simulations of the thermal history. Based on the resulting structural evolution, we calculated stresses in the viscoelastic ice region due to the solidification of the liquid water. Europa's liquid layer solidifies slowly and may partially survive at present, and its solidification induces sufficient tensional stress to drive extensional tectonic activity. Moreover, we investigated the possibility that solidification of subsurface water reservoir in Enceladus can attain enough excess pressure to explain the geysering. If the viscosity of the surrounding ice is viscous enough to inhibit relaxation, as high as 10^20-21Pas, sufficient excess pressure can be accumulated and the crack will be created to drive the internal water to the surface.

第16回宇宙科学シンポジウム (2016年1月6日-7日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, 16th Space Science Symposium (January 6-7, 2016. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)Sagamihara Campus), Sagamihara, Kanagawa Japan, 著者人数: 15名, 資料番号: SA6000046115, レポート番号: P-116

第16回宇宙科学シンポジウム (2016年1月6日-7日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, 16th Space Science Symposium (January 6-7, 2016. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)Sagamihara Campus), Sagamihara, Kanagawa Japan, 著者人数: 11名, 資料番号: SA6000046112, レポート番号: P-113

The models for stress in the ice shell produced by a pressurized subsurface water reservoir due to solidification are presented. Cassini-Huygens spacecraft has revealed active jets of water vapor and ice particles emanating from the south polar region of Enceladus. One conceivable scenario is that the plume is generated from a subsurface liquid water reservoir and results in a cryovolcanic eruption through the conduit in the icy shell. We investigate the possible role of tectonic stress and overpressure due to gradual solidification of water reservoir exceeding the strength of ice to induce cracking and to drive the cryovolcanic eruption. The stability and solidification process of the subsurface isolated liquid water reservoir to ambient colder icy shell and the resulting stress in surrounding ice shell due to volume increase arising from solidification of the reservoir are numerically investigated. Here we report preliminary results of theoretical verification of the subsurface reservoir scenario., 資料番号: AA0063723035

The source mantle of the basaltic ocean crust on the western half of the Pacific Plate was examined using Pb–Nd–Hf isotopes. The results showed that the subducted Izanagi–Pacific Ridge (IPR) formed from both Pacific (180–∼80 Ma) and Indian (∼80–70 Ma) mantles. The western Pacific Plate becomes younger westward and is thought to have formed from the IPR. The ridge was subducted along the Kurile–Japan–Nankai–Ryukyu (KJNR) Trench at 60–55 Ma and leading edge of the Pacific Plate is currently stagnated in the mantle transition zone. Conversely, the entire eastern half of the Pacific Plate, formed from isotopically distinct Pacific mantle along the East Pacific Rise and the Juan de Fuca Ridge, largely remains on the seafloor. The subducted IPR is inaccessible; therefore, questions regarding which mantle might be responsible for the formation of the western half of the Pacific Plate remain controversial. Knowing the source of the IPR basalts provides insight into the Indian–Pacific mantle boundary before the Cenozoic. Isotopic compositions of the basalts from borehole cores (165–130 Ma) in the western Pacific show that the surface oceanic crust is of Pacific mantle origin. However, the accreted ocean floor basalts (∼80–70 Ma) in the accretionary prism along the KJNR Trench have Indian mantle signatures. This indicates the younger western Pacific Plate of IPR origin formed partly from Indian mantle and that the Indian–Pacific mantle boundary has been stationary in the western Pacific at least since the Cretaceous.

第48回月・惑星シンポジウム (2015年7月29-31日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)), 相模原市, 神奈川県, 48th ISAS Lunar and Planetary Symposium (July 29-31, 2015. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000045013

第48回月・惑星シンポジウム (2015年7月29-31日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)), 相模原市, 神奈川県, 48th ISAS Lunar and Planetary Symposium (July 29-31, 2015. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000045011

Voyager and Galileo images demonstrate that most of the major icy satellites have the extensional tectonic features. It has been thought that such tectonic features formed due to the surface extensional stress. In various sources of stress considered, contribution of the stress due to volume change accompanied by phase change is greatly important. In the icy satellites, solidification of the liquid water layer induces a large volume change, and for example, volume change rate due to the phase change from liquid water to low-pressure ice is about + 10 percent. In this paper, the Jovian satellite Europa has been focused on where only phase change to low-pressure ice occurs, and the stress has been evaluated numerically in the ice shell due to phase change. It is shown that the resulting stress exceeds the extensional strength of ice, and the surface fracturing can occur., 資料番号: AA0046650016

第15回宇宙科学シンポジウム (2015年1月6日-7日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, 15th Space Science Symposium (January 6-7, 2015. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)Sagamihara Campus), Sagamihara, Kanagawa Japan, 資料番号: SA6000034207, レポート番号: P-208

第15回宇宙科学シンポジウム (2015年1月6日-7日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県, 15th Space Science Symposium (January 6-7, 2015. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)Sagamihara Campus), Sagamihara, Kanagawa Japan, 著者人数: 14名, 資料番号: SA6000034209, レポート番号: P-210

A reasonable basis for future astronomical investigations of exoplanets lies in our best knowledge of the planets and satellites in the Solar System. Solar System bodies exhibit a wide variety of surface environments, even including potential habitable conditions beyond Earth, and it is essential to know how they can be characterized from outside the Solar System. In this study, we provide an overview of geological features of major Solar System solid bodies with minor atmospheres (i.e., the Terrestrial Moon, Mercury, the Galilean moons, and Mars) that affect surface albedo at local to global scale, and we survey how they influence point-source photometry in UV, visible, and near IR (i.e., the reflection-dominant range). We simulate them based on recent mapping products and also compile observed light curves where available. We show a 5-50% peak-to-trough variation amplitude in one spin rotation associated with various geological processes including heterogeneous surface compositions due to igneous activities, interaction with surrounding energetic particles, and distribution of grained materials. Some indications of these processes are provided by the amplitude and wavelength dependence of variation in combinations of the time-averaged spectra. We also estimate the photometric precision needed to detect their spin rotation rates through periodogram analysis. Our survey illustrates realistic possibilities for inferring the detailed properties of solid exoplanets with future direct imaging observations., 8 figures, 3 tables, Astrobiology, in press