This paper concisely describes the land mammal faunas of the last glacial period and Holocene separately for the three biogeographic regions comprising the Japanese Islands (Hokkaido, Honshu-Shikoku-Kyushu and the Ryukyu Islands). It also outlines the extinctions and immigration of land mammals during the periods. In Hokkaido, the fauna of the last glacial period is represented only by a few extinct large mammal species. It is inferred that the Mammoth Fauna immigrated from eastern Siberia into Hokkaido during this period. The large mammal species of the last glacial period became extinct possibly by the beginning of the Holocene. The Holocene fauna of Hokkaido is almost idenfical with its present-day fauna, and no mammals immigrated into Hokkaido during the Holocene. In Honshu-Shikoku-Kyushu, the last glacial fauna is predominated by extant species now distributed in this region, and contains several extinct species as well as several extant species now exotic to this region. The extinct and exotic species seem to have become extinct between ca. 20,000 and ca. 10,000yrsBP in radiocarbon age. During the last glacial period, few elements of the Mammoth Fauna immigrated into Honshu-Shikoku-Kyushu from Hokkaido. Such limited immigration is inferred to have occurred through temporary ice bridges formed across the Tsugaru Stait instead of a stable land bridge. In Honshu-Shikoku-Kyushu, the Holocene fauna is almost identical with the present-day fauna, and no mammals immigrated into this region during the Holocene. In the Ryukyu Islands, the last glacial fauna is of insular type, and its main elements including middle- and small-sized deer became extinct possibly by the beginning of the Holocene. No mammals immigrated into the Ryukyu Islands during the last glacial period and Holocene.

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This paper discusses the procurement and utilization of obsidian by the microblade industries of the terminal Late Palaeolithic in the Chubu and Kanto districts of central Japan at the end of the last glaciation, 18,000-16,000 cal BP. The core of the discussion is based on the source determinations for 4,000 obsidian artifacts from sites in these two regions.
The sourcing results identified obsidians from five groups of sources in the Chubu and Kanto districts-Wada-Suwa, Tateshina, Kozushima, Hakone and Amagi-and procurement and utilization of all five sources in the microblade industries in the same districts. Among these sources, both Wada-Suwa and Kozushima obsidians were identified in sites over 200km from the sources, indicating development of wide zones of utilization. Possible strategies for using these sources include direct procurement, trade, and embedding (in seasonal rounds). Which strategy, or strategies, was actually used is not known at this moment.
There was a distinct increase in the use of obsidian from the Kozushima source, on an island in the Pacific Ocean, by the microblade industries, compared to earlier phases of the Late Palaeolithic. The microblade-technology revolution for the efficient use of lithic resources and the aggressive development of obsidian sources on distant islands reflect a strategy of the peoples in the Japanese Islands for adapting to the rapid changes in the environment at the end of the Pleistocene.

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Intensive research into the radiocarbon dating of the Jomon pottery chronologies, especially on the Kanto Plain in central Japan, has made it possible to examine the temporal correspondences between environmental changes and human activities during the Holocene, from ca. 11,500 to 2,800 cal BP. This paper sets out five environmental events (IV to VIII, dated as 11,500, 8,400, 5,900, 4,500, 3,000 cal BP) and five environmental stages (Stage IV to Stage VIII) based on comparisons between environmental events detected on the Kanto Plain and the high-resolution environmental reconstructions reported in recent studies. Compiled radiocarbon dates of pottery-type chronologies from Earliest to Latest Jomon were calibrated to compare with these environmental events and stages. The results show that Stage IV (ca. 11,500-8,400 cal BP) correlates with pottery types from the early Yoriitomon pottery group to the Nojima type, Stage V (ca. 8,400-5,900 cal BP) with types from the Ugashimadai type to the Moroiso-a type, Stage VI (ca. 5,900-4,500 cal BP) with types from the Moroiso-b type to the Kasori-E4 type, Stage VII (ca. 4,500-2,800 cal BP) with types from the Shomyoji-1 type to the Angyo-3c type, and Stage VIII (ca. 2,800 cal BP and younger) with the Angyo-3d type and subsequent types. Now it is necessary to study and develop more accurate pictures of human adaptations to the environmental changes based on more detailed environment-culture correlations.

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High-resolution as well as high-precision age estimation is particularly important for Quaternary research to realize its main aim of better understanding of global environmental changes of the past and realistic prediction of the changes in the near future. Among several dating methods that are applicable to Quaternary samples, radiocarbon (¹⁴C) dating has been commonly used since its development in late 1940s.
A new ¹⁴C detection technique, accelerator mass spectrometry (AMS), has been developed since 1977. The method directly detects and counts ¹⁴C atoms, instead of counting β-ray emitted in the decay of ¹⁴C, and therefore requires only a few mg of carbon for ¹⁴C measurements. Nowadays, AMS ¹⁴C dating is widely used and more than sixty AMS ¹⁴C facilities are in operation in the world. In Japan, eight facilities for AMS ¹⁴C dating have been in use since 2004.
As one of the eight AMS ¹⁴C measurement systems in Japan, the Nagoya University AMS group has started routine ¹⁴C measurements with the firstly introduced Tandetron AMS system since 1983 and also with the secondly established Tandetron AMS since 1999. The second system has an excellent performance of the standard deviation (one sigma) of the ¹⁴C/¹²C ratios of around ±0.2% to ±0.4% (±17-±30 ¹⁴C yrs) and that of the corresponding ¹³C/¹²C ratios of ±0.03% to ±0.07%, as are tested for HOxII targets. By using this AMS system, we are now trying to provide accurate ages to the Quaternary events. Briefly discussed in this article are, (1) a consistency test of the established IntCal98 and IntCal04 ¹⁴C data sets with the ¹⁴C-concentration records in Japanese tree rings ; (2) programs of high accuracy and precision age estimation by ¹⁴C wiggle matching techniques for wood samples ; (3) investigations of ¹⁴C reservoir effect for marine samples from the Japanese Archipelago.

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A number of studies on lithostratigraphy and marine microfossil biostratigraphy has been conducted on the representative Pliocene to Lower Pleistocene formations in Japan. In recent years, new widespread tephra beds connecting the Pliocene to Lower Pleistocene formations in various areas have been discovered. The present work introduces the latest stratigraphic studies on the Pliocene to Lower Pleistocene formations in various regions. Further, it examines the relationship between extensive tephra beds as contemporaneous marker horizons and biostratigraphy of calcareous nannofossils and diatom fossils.

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Stratigraphic studies of magnetic polarity, paleobotany, and paleoenvironment using Plio-Pleisotocene terrestrial sediments in Japan and north central China were reviewed to investigate climate changes around the Gauss-Matuyama magnetic polarity boundary (GMB). Pollen and plant macrofossil data from Osaka, Aizu, and Tokachi in Japan show an extensive floral change associated with cooling in the latest Gauss chron, which is the largest in scale during the last 3-5 million years. The floral change occurred within a zone just below the GMB, where warmer elements disappeared stepwise and new cooler elements emerged also stepwise. In Tokachi, northern Japan, a long-term warmer climate that began at about 3.7Ma terminated just before the GMB, followed by recovery of a boreal climate. In the Chinese Loess Plateau, the GMB occurs around the loess/red clay boundary (LRB). However, the GMB lies at various depths ranging from 5m to -4m above the LRB, which is too wide to be explained by downward displacements due to delayed acquisition of post-depositional remanent magnetization. Local climates may have originated regional variability in lithology. The strong cooling event predating both the GMB and the LRB is consistent with that observed in Japan. Magnetic susceptibility of the red clay suggests occurrence of a long-term warm-moist climate from 3.4Ma to 2.75Ma, which may be related to that in Tokachi.

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Large numbers of oxygen isotopic curves of benthic foraminiferal tests from deep-sea sediment cores have been published. The curves are well-established reliable proxies for past climate and relative sea level fluctuations. In order to understand possible trends in the future climate, a precise identification of warmest events in the past interglacial records becomes a necessity. In this review, we have compared nine hitherto published high-resolution oxygen isotopic records of the last 420 thousand years in order to understand the intensity of the past warm events during interglacial periods. The rating of the intensity of the interglacial events as depicted by the oxygen isotopic variability is as follows ; Marine Isotope Stage 5.5>9.3>11.3>1>7.5. This rating of interglacial warming is closely comparable with the standard oxygen isotope curve of deep-sea sediment cores and also to the hydrogen isotope curve of the EPICA Dome C ice core from the Antarctica. The remarkably high sea level during the warmest interval within MIS 5.5 reached about 7±4m above the sea level during MIS 1, and even possibly above the present-day sea level. The MIS 11.3 periods is distinctive as the longest warm period among the last five interglacial periods. This observation clearly suggests that detailed studies of MIS 5.5 and 11.3 are essential for the prediction of the future environment of the Earth under the global warming.

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Paleoclimate of interglacial Marine Isotope Stage 11 (MIS 11), about 400 ky ago was estimated using data from shallow-marine to terrestrial strata of the Japanese Islands. The reason of the estimation comes from that the paleoclimate gives analogs for the future climate, because the conditions of Milankovitch forcing of MIS 11 are similar to those of modern Holocene. The results show the MIS 11 of the Japanese Islands was warmer, with a longer interval of highstand, and higher sea levels than the other interglacials. Further investigation for the strata of MIS 11 of the Japanese Island is needed and will give us important information about our future climate.

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The current status and some problems of the Japanese surface pollen dataset are reviewed in an attempt to improve paleotemperature reconstructions for late Quaternary interglacials (MIS1, 5e and 11), which may provide analogues for present global warming. Application of modern analogue technique (MAT) to a 250m-long pollen profile from Lake Biwa provided quantified paleotemperature variations during the past 450kyr, with the limitation that the reconstructed curve saturates above 16°C annual mean temperature, resulting in low accuracy for reconstructed interglacial thermal levels. This saturation results from a lack of surface pollen in the same thermal range. In order to resolve this problem, a surface pollen data addition for the warm-temperate zone of Japan along the southwestern Pacific coast is being carried out.

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The issue of what the modern world call ‘global warming’ is the climate change primarily due to carbon dioxide released by burning of fossil fuel. Carbon dioxide has a capability to absorb and emit infra-red radiation, and thus acts as a forcing to the climate system. It is expected that climate will warm responding to the forcing. The temperature response will be delayed by several decades because of the heat capacity of the upper ocean, and the sea-level response will be delayed by a millennia because of the response times of the whole ocean and the continental ice sheets. As the climate warms, both precipitation and evaporation will increase in the global average sense, but the increase is not so strong as the increase of saturation specific humidity. On the other hand, local and short-term extreme values of precipitation rate will surely increase. Distribution of precipitation will be more heterogeneous. Paleoclimatological evidence suggests that there are possibilities of rapid climate changes which are not well represented by current numerical climate models used in projection experiments. We should not deny the possibilities of such ‘surprises’, but we are very uncertain about their probability. It would be wise approach to primarily prepare for the climate responses as projected by an ensemble of current state-of-art simulation models, and to secondarily prepare for various uncertain events which include climate ‘surprises’.

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Perturbations of Earth's rotation and tide gauge data with information for relative sea level during the past 140-200 years were analyzed to examine the rates and causes of twentieth-century global sea level rise. Relative sea levels based on tide gauge data are sensitive to both the meltings of the polar ice caps and mountain glaciers and thermal expansion of seawater associated with the global warming. Changes in Earth's rotation are, however, insensitive to the thermal expansion. I compared the observations with predictions due to the meltings of both polar ice caps and examined the causes and rates of twentieth-century global sea level rise by considering the sensitivities of these observables. The present study suggests that the meltings of the Greenland ice sheet and Antarctic ice sheet around the Weddell Sea have equally contributed to the global sea level rise of ∼0.5mm/yr. The rates of the global sea level rise may be larger than ∼1.3mm/yr. It is, however, impossible to determine the components of the thermal expansion of seawater and melting of the mountain glaciers independently.

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Major reclamation projects have resulted in large impacts on the natural environment of coastal areas worldwide. We investigated faunal changes in benthos following the construction of reclamation dikes in the area of Saemangeum, on the western coast of South Korea, and compared them with those in Isahaya Bay, Japan. The world's largest reclamation dike was constructed in Saemangeum. Following its completion in April 2006, the tidal flats in this area gradually dried out, and we confirmed that numerous dead shells of mollusks and other benthic animals were exposed on the dried tidal flat in June 2006. The inner part of Isahaya Bay was isolated from the rest of Ariake Bay by a reclamation dike in April 1997. The intertidal zone of this bay also dried out completely within several months, and numerous dead shells were exposed on the dried mud flats. Changes in benthic fauna were also confirmed in the outer part of Isahaya Bay. Red tides and hypoxic water have frequently been observed, and the numbers of many bivalve species have decreased rapidly since 1997. Similar changes have already been confirmed in the outer parts of the Saemangeum dike. These facts suggest that the Saemangeum dike will negatively affect the Yellow Sea in the near future.

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Fly-ash particles such as spheroidal carbonaceous particles (SCPs) and inorganic ash spheres (IASs) in sediments indicate modern fossil fuel combustion. A lake or pond away on the leeward of industrialized areas accumulates these particles in sediments to record the temporal change of fossil fuel combustion in the industrialized areas. The authors analyzed the fly-ash particles in a sediment core from Oike Pond in Oki Islands in the Japan Sea. The age of the core covers the last 100 years. The amount of both SCPs and IASs gradually increases from 1950s to the present. SCPs appear for the first time around the 1950s, while IASs have appeared around the 1920s. The profiles of lead and mercury concentration are similar to the profiles of the fly-ash particles. This evidences the increase of air-pollutants by coal combustion. The primary source of the IASs and SCPs is supposed to be coal combustion. The SCPs profile from Oike Pond resembles to that of Taihu Lake in eastern China after 1950s. Therefore the IASs deposited in Oike Pond after 1950s are inferred to have derived from China following increased coal consumption.

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Japanese tephra studies have developed steadily in the last five decades. First two decades until 1976 brought fundamental ideas and techniques for correlation and for recognition of widespread co-ignimbrite ash falls. Geochemical and physical characterization of tephras advanced greatly in the third decade in 1980s. This enabled identification and distinction of many individual tephra layers and then compilation of tephra catalogs for solid tephrostratigraphic framework. VEI=7 classed large-scale eruptions had occurred at several calderas in Kyushu and Hokkaido Islands during the period from Middle Pleistocene to Holocene. Estimated average frequency is once in every a few ten thousand years. Their impacts on human society and ecosystem were analyzed through many disciplines of Quaternary research and turned out to have been very severe. Late Pleistocene and Holocene eruptive histories of medium-scale Plinian eruptions (VEI=4-6) are mostly documented and included in catalogs. Studies on their impacts on humankind during both pre-historical and historical ages confirmed severe volcanic hazards. The knowledge makes long-term prediction and volcanic hazard mitigation more reliable. Detailed stratgraphic and chronological studies on Holocene pyroclastic deposits helped to establish precise eruptive histories of some active volcanoes. Many recent works focused on Pliocene to Middle Pleistocene widespread tephras. Middle Pleistocene tephrochronology has provided information on regional changes of the frequency and magnitude of eruptions and magma discharge rate as a function of time. Studies of older distal tephras preserved in non-volcanic sediments let us know the occurrence of large-scale eruptions without any volcanic edifice preserved. The 10⁵ to 10⁶ year scale tephrochronology is revealing very long-term evolution of volcanic activity and magma discharge.

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Large tsunamis are important not only as a serious natural disaster but also a controlling factor in coastal sedimentation processes. Tsunami deposits have been studied in both geological and disaster prevention fields and play an important role in connecting these studies. Large tsunamis cause rapid and large-scale sediment transport in lacustrine, coastal, shallow-marine and deep-marine environments. They play a positive role to form and preserve sand, gravel and shell beds in the geological record. Tsunami deposits probably occupy significant part of coastal geological strata.
Tsunami deposits in the geological records help us to estimate the recurrence interval of subduction-zone earthquakes that cause tsunamis. Histories of such earthquakes inferred from tsunami deposits span 3,000 years for the Nankai and Suruga Troughs, nearly 10,000 years for the Sagami Trough and 6,500 years for the southern Kuril Trench. Tsunami deposits also aid in estimating the relative size of paleo-tsunamis. Studies in eastern Hokkaido, north Japan, revealed the repeated occurrence of unusually large tsunamis with inundation of several kilometers. These mega-tsunamis have occurred at about 500-year-intervals over the last 6,500 years along the southern Kuril Trench.
Although some problems and difficulties remain, tsunami deposits are useful for reconstructing tsunami history and evaluating risk of future tsunami events. With the development of methods for differentiating tsunami deposits from other event deposits, and evaluating the hydraulic force and inundation depths, we will be able to learn much about past tsunamis from the deposits and to make use of such information for disaster prevention. Collaboration of a broad range of scientists and engineers, such as geologists, geomorphologists, seismologists, geophysicists and tsunami engineers, would enable to solve existing problems in paleo-tsunami research.

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