著者

浜野 洋三

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.101, no.6, pp.430-441, 1992-12-05 (Released:2009-11-12)

著者

盛谷 智之

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.87, no.4, pp.181-200, 1978-08-25 (Released:2009-11-12)

参考文献数

40

---

Ocean floor manganese nodules have attracted worldwide attention as the possible future resources. However, many problems in the distribution and origin of the nodules remain still unsolved, because of the lack in reliable seabed information. Thus, several leading ocean-oriented countries are now carrying out, or have plans about the systematic research programs on manganese nodules, including both prospectings mainly by industry groups, and scientific studies by the governmental and university groups, in which the results of the latter scientific studies are expected to serve as the guideline for the former prospectings. The representative programs are as follows : In Japan, “Basic researches on the deep sea mineral resources” is being conducted by the Geological Survey of Japan, for the northern Central Pacific Basin, using R/V Hakurei-Maru (1, 821 tonnage), with participation of the NIPR (National Institute for Pollution and Resources) in each cruise on their own program, “Technological study on the development of deep sea mineral resources”. Also, the industries group, DOMA (Deep Ocean Minerals Association), is engaged in a program of “Development of new prospecting technology for manganese nodule deposits”, with the objective areas south of Hawaii Islands of the Pacific.In the United States, there are three categories of research programs, being actively conducted by the groups of universities, Federal organizations, and industries respectively. The first is “MANOP (Manganese Nodule Program) of NSF (National Science Foundation) Seabed Assesment Program, carried out by the interuniversities group. This is now concentrated on the detailed studies of the sea floor to obtain its real physical, geochemical and biological informations by means of the in-situ measurement instruments, deployed in each representative area of different sedimentological condition of the Pacific. The second is “DOMES (Deep Ocean Mining Environmental Studies)” of the Office of the Marine Minerals, NOAA (National Oceanic and Atmospheric Administration), in which the research groups from the Federal organizations such as NOAA and U.S. Geological Survey are in charge of conducting its geological aspects. The third are the programs of the industry groups related to the commercial development of manganese nodules, including prospecting, mining and processing. Four major international consortiums, Deepsea Ventures Group (OMA, Ocean Mining Association), INCO Group (OMI, Ocean Management Inc.), Kennecott Group (Kennecott Exploration), and Lockeed Gr oup (OMC, Ocean Minerals Co.) are now developing their programs, aiming at mining operation tests in the Pacific as immediate objectives.In West Germany, a program, “Researches on manganese nodules”, is actively promoted under the coordination and sponcering of the Ministry of Research and Technology, with participation of the Federal Institute for Geoscience and Natural Resources, universities and industries association (AMR, Arbeitsgemeinschaft meerestechnisch gewinbare Rostoffe), using R/V Valdivia (1, 317 tonnage), for the objective areas between Clarion and Clipperton fracture zones of the Pacific.In France, CNEXO (Centre National pour L'Exploitation des Oceans) and its research group, AFERNOD (Association Francais d'Étude et de Recherche des Nodules océaniques) are carrying out “Rsearches on polymetallic (manganese) nodules”, mostly for the southern Central Pacific Basin.In England, a research group has done recently some research cruises on the manganese nodules and metalliferous sediments for the Indian Ocean.

著者

小泉 武栄

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.98, no.1, pp.73-81, 1989-02-25 (Released:2009-11-12)

参考文献数

7

著者

斎藤 実篤

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.100, no.4, pp.616-627, 1991-08-25 (Released:2010-11-18)

参考文献数

45

被引用文献数

1

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Structural characteristics of Recent forearc regions can be divided into three types (shelf type, terrace type, slope type) in terms of the morphology of forearc basins and the topography of basements. The differences in forearc structure seems to correspond with the difference in deformation style of forearc lithospher by subduction. Supply and/or subduction of sediments at trench are secondary factor of forearc deformation. High plate convergence rate leads to widely uplifting of island arc less subsidence of forearc basin (shelf type). Conversely, low plate convergence rate leads to one-sided subsidence of trench side and increasing in undulation of forearc topography (slope type).Sediments from forearc basin can reconstruct the subsidence rate of forearc basin and the vertical movement of island arc and by use of planktonic microfossils and benthic for eminifera which determine the changes in sedimentation rate and paleobathymetry. Thus, forearc basins are tectonic recorder to estimete the arc evolution and the change in subduction styles.

著者

安田 喜憲

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.94, no.7, pp.586-594, 1986-01-25 (Released:2009-11-12)

参考文献数

59

被引用文献数

1 1

著者

鈴木 康弘 渡辺 満久 廣内 大助

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.113, no.6, pp.861-870, 2004-12-25 (Released:2009-11-12)

参考文献数

9

被引用文献数

8 9

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The surface faults of the Mid Niigata prefecture Earthquake in 2004 appeared along preexisting active fault traces (lines) of the Obirou fault, as well as the northern part of the western marginal fault of the Muikamachi basin. The vertical displacement of surface faults are within 30 cm, and the three areas with distinct faults can be summarized as follows. At Obirou, in Hirokami village (Uonuma city), the road surface is vertically displaced by approximately 30 cm just along the active fault line, and the waterways located on the fault line are compressed and broken. At Shitakura, in the Horinouchi town (Uonuma city), the surfaces of both the highway and the old road are cracked and vertically displaced by approximately 20 cm. At Aoshima, in Koide town (Uonuma city), the surface faults clearly extend over 500 m in length. Paddy fields, gardens, waterways, roads, and houses are vertically displaced by approximately 20 cm. The facts mentioned above indicate that the Mid Niigata prefecture Earthquake in 2004 (probably the main shock) was caused by the rejuvenation of these active faults.

著者

吉井 敏尅

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.94, no.7, pp.648-655, 1986-01-25 (Released:2009-11-12)

参考文献数

8

著者

石村 満宏

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.94, no.4, pp.256-265, 1985-08-25 (Released:2010-10-13)

参考文献数

16

被引用文献数

1

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.25, no.11, pp.814-814, 1913

著者

中田 高 堤 浩之 PUNONGBAYAN Raymundo S. RIMANDO Rolly E DALIGDIG Jessie DAAG Arturo

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.99, no.5, pp.515-532, 1990

被引用文献数

5 13

---

The Philippine Earthquake (Ms=7.8) broke out in July 16, 1990 along the Philippine Fault in Central Luzon. The Philippine Fault is seismically very active and large earthquakes of M 7 class have occurred during this century along this fault. However large earthquakes have not taken place along the active traces of the fault in the Central Luzon during this century, while two large historical earthquakes occurred along its southern trace in 1645 and its northern trace in 1796. Therefore it is considered that the 1990 earthquake was caused by the surface faulting in the seismic (aseismic) gap along the Philippine Fault.<BR>The total length of the surface fault is over 120 km and the fault is divided into two segments by the major bend near Rizal. The surface fault is rather straight and linear and general orientation of the northern segment is N 25 W and the southern segment N40W. Left-lateral displacement is dominant along most of the fault traces and the maximum horizontal displacement is about 6 m in the 60-km-long northern segment and the maximum vertical displacement is 2.0 min the 50-km-long southern section. Sense of vertical displacement changes in places and is consistent with the sense of the displacement along the pre-existing active fault traces. Average displacement along the northern segment is 5-6 m, while 2-3 m along the southern segment.<BR>Along most of the surface fault, ruptures appear exactly along the pre-existing active fault traces. Offsets of roads, foot-pass, streams are common earthquake-induced features. Local extensional and compressional jog forms related to slight change in fault strike creates characteristic features such as depressions, trenches, mole tracks, bulges etc.<BR>The rupture propagated bilaterally northward and southward from hypocenter east of Bongabon near the major bend. The source process of the earthquake deduced from the slip distribution along the surface fault from the epicenter well coincides with that deduced seismologically from the source time function.

著者

尾留川 正平 山本 正三 佐々木 博 金藤 泰伸 朝野 洋一 高橋 伸夫 斎藤 功

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.76, no.5, pp.229-256, 1967-10-25 (Released:2009-11-12)

参考文献数

20

被引用文献数

3

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Suburbanization is very phenomenal in the western suburbs of Tokyo, nevertheless a. sizable area is still devoted to agriculture and the agricultural output is quite large. The aim of this research is to survey the ecological aspects of human occupance of the land which is well characterized by the ever intensive urban as well as agricultural use and also to analyze operational structure of farm households that has strongly led the study area to such a suburbanized occupance pattern in terms of interviews of farmers and various statistical materials.Results : 1) Sale of agricultural land is quite limited because of rise of land price, resulting in the juxtaposition of built-up areas and farmlands. 2) Agriculture in these mostly built-up areas has the following characteristics : a) to increase labor productivity rather than land productivity, b) to increase household or personal income whether by specialization on arboriculture, lawn growing, specialized vegetable growing and chicken and pig raising, or by incorporating them in agricultural management so as to improve total agricultural productivity, or from other sources than farming such as management of filling stations, driving, schools, and public baths, and also as white color, c) to hold agricultural land as assets probably for a relatively long period, since the farmers here can get stable income from rent and apartment houses they have built recently, although increment of so-called socially fallow lands is to be seen frequently, and d) to ship out vegetables and eggs to nearby markets or to sell them directly at farmsteads. 3) It is urgently needed to conserve as much farmland as possible and also even to encourage farm management to a degree that the farmers are able to compete with ever-developing urban industries, otherwise the critical shortage of green open spaces in the metropolitanized regions will be further accelerated.

著者

佐藤

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.21, no.12, pp.847a-848, 1909

著者

菅原 正巳

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.94, no.4, pp.209-221, 1985-08-25 (Released:2010-12-22)

被引用文献数

3 4

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The tank model is very simple as shown in Fig. 1. We can consider that it corresponds to the zonal structure of groundwater as shown in Fig. 2. In spite of its simple outlook, the behaviour of the tank model is not so simple. Corresponding to various types of input rainfall, it shows various types of response as shown in Fig. 5 by its nonlinear structure caused by the positions of side outlets which are set somewhat higher than the level of the bottom.The tank model shown in Fig. 1 is used to calculate the daily discharge from the daily precipitation for Japanese river basins. For the flood analysis, data of short time unit are necessary and an appropriate time unit is suggested to be given asT.U.=0.05√A, where T.U. is the time unit (hour) and A is the catchment area (km2). Table 1 shows some examples of appropriate time unit for various catchment areas. For the flood analysis the tank model with two tanks shown in Fig. 6 is applicable.In Japan, the tank model without soil moisture structure can give fairly good results because it is always very humid in Japan. However, for most river basins, the tank model with soil moisture structure shown in Fig. 7 must be applied. The assumed soil moisture structure is composed of two parts, the primary and the secondary soil moisture storages. When the primary soil moisture storage is not saturated, the water is absorbed from the lower tank and there is water transfer between the primary and the secondary soil moisture storages. These two kinds of water transfer are given as shown in Fig. 7c.In regions with long dry season, there is no tree on mountain area or trees have no leave in dry season and vegitation covering can be found on plains or along rivers. In such regions, mountain areas become dry during the dry season, because water moves to lower part of the basin by gravitation. To simulate such a basin, the basin is divided into zones each of which is simulated by the tank model. The tank model of 4X4 type shown in Fig. 8 is derived under such a consideration. During the dry season, zones become dry from mountain side and no evapotranspiration occurs in dry zones. In this model real evapotranspiration from the basin decreases with time corresponding to the dry condition of zones, i.e. areal real evapotranspiration of the basin decreases automatically.The tank model is considered as a black box model without physical meaning by most hydrologists. However, we can ask ourselves, if it is a mere black box, how can such a simple tank model successfully simulate river discharge from high flood to low base flow? There must be some physical meaning in the tank model. Very recently, we were able to find the phenomenon to prove the existence of two kinds of water storage corresponding to the top and the second tank of the tank model by analysing the record of crustal tilt meters affected by rainfall (Fig. 9). The crust is some sort of spring balance which weighs' and so measures the groundwater storage (Fig. 10).

著者

佐渡 耕一郎 亀尾 浩司 小西 健二 結城 智也 辻 喜弘

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.101, no.2, pp.127-132, 1992-04-25 (Released:2010-10-13)

参考文献数

20

被引用文献数

8 7

---

Three nannofossil datum planes of the Early Pleistocen e are identified in the cores from subsurface at Irabu Island, South Ryukyus. The result allows for the first time to date the initial sedimentation of the reef-related Riukiu Limestone there. It represents the age (1.2M a) turning from siliciclastics to shallow-water carbonate regime. Implication of this transition time is discussed briefly in relation with both local neotectonis m resulting in the birth of a backarc basin (Okinawa Trough) and regional to global reor ganization of paleoceanographic environments.

著者

井関 弘太郎

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.84, no.5, pp.247-264, 1975-10-25 (Released:2009-11-12)

参考文献数

52

被引用文献数

5 10

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Alluvial plains in the coastal regions of Japan are considered to have developed according to the following processes : during the last glacial stage when the sea level was lowered, rivers dissected their valleys downward to that level. After then, in consequence of the postglacial rise of the sea level, these valleys were drowned and were filled up with Flandrian deposits.The bottom floors of such buried valleys are mostly found at 30-80 meters below the present sea level. These bottom floors in many cases are covered with fluvial gravel beds about 10-20 meters thick. Such gravel beds are mostly overlaid with sediments of finer materials which deposited in the shallow sea during the late and post glacial transgression. They are called “Basal Gravel Beds” of the Recent deposits by the present author. They have probably been formed when the lowering of the sea level reached the limit during the last glacial stage. The huge accumulation of gravels as the Basal Gravel Beds might have been brought on by the overloaded streams which carried much detritus as the production of the strong physical weathering under glacial or periglacial conditions during the Ice Age. The author found that some of the Japanese alluvial fans of a large scale are formed by Recent Basal Gravel Beds.The maximum accumulation of the ice during the last glacial stage should be enough to cause a lowering of the sea level of about 80-15 meters below that of the present. In order to get a acceptable figure regarding the lowering of the sea level or the lowest sea level during the last glacial stage, the author, presuming the figures-100 and-140 meters as the postulated low sea level stand, examined the depth of these floors of buried valleys, respectively.Based on the results of borings which were carried out with 21 major buried valleys in Japan, the depth from the surface of present-day alluvial plain to the upper face of Basal Gravel Bed which covered bottom floor of buried valley was measured in each alluvial plain and then the relation between the depth of the deepest bore hole and the distance from the mouth of the old valley to that bore hole site was investigated (Fig. 3 and 4). The correlation coefficient between the depth and distance was also calculated.Fig. 3 indicates the case in which the sea level was presumed to be 100 meters below that of the present and Fig. 4 in the cases of-140 meters, respectively. Is is obvious from these two charts that the depth of the deepest bore hole negatively correlates with the distance from the mouth of buried valley to that bore hole site. So far as the correlation coefficients are concerned, being-0.870 and-0.890, respectively, the presumed figure of the latter seems to be more acceptable than that of the former. Therefore, judging from the depth of buried valley floors, the author is of the opinion that the figure-140 meters as the lowest sea level during the last glacial stage should be more acceptable than that of-100 meters.

著者

池原 研

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.107, no.2, pp.234-257, 1998-04-25 (Released:2009-11-12)

参考文献数

134

被引用文献数

1 1

---

Marginal seas, such are located as Bering Sea, Okhotsk Sea, Japan Sea, East China Sea, South China Sea and Indonesian seas, locate along the western rim of the Pacific. They have only a small area but are regions of high biological productivity, and thus expected to play an important role on global environment. Each of them has an unique characteristics on bathymetry, water exchange between the adjacent marginal seas and/or open ocean, primary productivity and volumes of fresh water input and terrigeneous material supply. Because they connect each other and to the open ocean through the shallow straits, characteristics of water masses flowed into the marginal seas were highly influenced by global sea level fluctuations. Furthermore, climatic change affected the volume of terrigenous supply to the seas. Therefore, paleoenvironments of the marginal seas largely changed with long-term sea level changes and short-term climatic changes. Recent studies on paleoceanography of the Japan Sea and the South China Sea suggest the importance of Asian monsoon to control the oceanic environments of the marginal seas. Hemipelagic sediments with higher sedimentation rates in the marginal seas recorded paleoceanographic changes in high resolution. Multidisciplinary studies for large-diameter long piston cores from the East Asian marginal seas may provide good information for global climate changes in the late Quaternary.

著者

石川 有三

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.110, no.4, pp.592-601, 2001-08-25 (Released:2009-11-12)

参考文献数

26

被引用文献数

4 5

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The shape of the Philippine Sea slab beneath southwest Japan was investigated using the hypocenter distribution and the fault plane solutions obtained by Japan Meteorological Agency. Two seismic belts were found in an equal depth section of the slab and these did not relate to the double seismic zone in the subducting slab. Then, the existence of a broken off piece of slab was proposed beneath Kii channel. This piece collided with Philippine Sea slab and created a high seismicity area at each side.Three events that were not located at a high seismic area in the slab were found. Two were considered to be the events that occurred at the near aseismic part of the slab. The other may have occurred at another broken off piece of the slab.

著者

ダビターヤ F. F.

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.76, no.3, pp.154-158, 1967

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自然は絶えず変化している。自然のままの状態では気候の変化が最も速やかに行なわれ, 植生や地形の変化は何世紀, 何十万年という速度で進行する。しかしいったん人為が加わるとそれぞれ変化の速度が異なってくる。人為の影響を受けやすいのは植生で, 気候はいちばん遅れて変化が現われるようになる。気候・植生・土壌などによる地域区分の境界線が一致しないのは, それぞれ変化の速度に違いがある以上当然だといえる。<BR>今世紀になってから人間の活動はますます活発になって, 森林の減少, 草原の砂漠化, 河川の汚染, 地たりの激化などが急速に進んでいるので, このままでは大きな弊害が生ずるであろう。影響を受けるのが遅いはずの気候でさえも人間の影響を無視できなくなってきている。Budykoの計算 (1962) によると年々太陽から得ている熱量は49kca1であるのに対して, 世界中の人間が出している熱量は0.02kcal/cm<SUP>2</SUP>/yrであるが, これが毎年10%ずつ増えているとすると100年以内に太陽からの熱量に匹敵する量になる。また, 人間活動によつて大気中の炭酸ガスの量が増加して気温が上昇することも考えられる。一方, 水蒸気量や雲量や塵埃量の変化がこれらの効果を強めたり弱めたりする。量的な研究はまだ進んでいない。<BR>最近50~100年間に気温の上昇が認められている。1940~50年から再び下降の傾向を示しているが, 上昇がもう終わってしまったのか, 一時的な変動であるのかは今のところわからない。気候の温暖化と氷河の後退との関係はなかなか複雑で一義的には決まらない。気候温暖化の主因は大気大循環にあると考えられているが, 地球全体が温暖化することを説明できない。炭酸ガス説も不十分である。人工発熱量も現在までのところ問題にならないくらい小さい。<BR>そこで気候温暖化の一因に大気中の塵埃量の増大が考えられる。ここに逆説的な観測事実が二つある。一つはコーカサスと中央アジア地方の高山で過去50~70年の間に, 降水量は同じか増加し, 気温は下降の傾向を示しているのに氷河が後退していること, もう一つは融けっっある氷の表面の温度が0度以上であることである。これらは最近大気中の塵埃量が増えてきていることで説明がっきそうである。<BR>大気中の塵埃は宇宙塵, 海成の塵埃, 火岸灰による塵埃, 風成の塵埃, 工業による塵埃などであるが, 最初の三つは少量で変化も小さい。大気中の全塵埃の70~75%を占める風成の塵埃は森林の伐採, 耕地の開拓などによつて近年急速に増加した。工業による塵埃も相当量にのぼる。ソ連各地の直達日射量の観測結果からも1920年ごろから塵埃量が著しく増加したことがわかる。<BR>このような最近の自然現象の変化の方向や強さを研究するためには, 全地球的規模の計画に従つて同時観測を実施することが必要である。そしてこのような観測の計画を樹てるためには世界各地の地理学者の協力がなければならない。

著者

新井 健司

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.105, no.4, pp.485-491, 1996-08-25 (Released:2009-11-12)

参考文献数

9

著者

大場 忠道

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.115, no.5, pp.652-660, 2006-12-25 (Released:2009-11-12)

参考文献数

11

被引用文献数

4 8

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Five distinct paleoenvironmental changes in the Japan Sea over the last 95 ka are revealedfrom the oxygen and carbon isotopes of foraminiferal tests in a piston core recovered from the Oki Ridge. Between 95 and 27 ka, the warm Tsushima Current did not flow into the Japan Sea.The environment at the seafloor fluctuated between anoxic to weakly oxic conditions. Between 27and 17 ka, freshwater input to the Japan Sea, probably from the surrounding land, stratified the water column, and the resulting severe anoxic conditions eliminated most benthic fauna. Between 17 and 10 ka, the cold Oyashio Current flowed into the Japan Sea through the Tsugaru Strait, reestablishing deepwater ventilation. Between 10 and 8 ka, bottom conditions changed from anoxic to oxic. At 10 ka, the warm Tsushima Current started to flow into the Japan Seathrough the Tsushima Strait, establishing the modern oceanographic regime at 8 ka.From high-resolution oxygen and carbon isotope analysis of both benthic and planktonic foraminifera from an IMAGES core collected from off Kashima, central Japan, very large (20°C) sea surface temperature (SST) fluctuations can be reconstructed for the last 150 kyr, with minimum SSTs of 3-4°C during Marine Isotope Stage (MIS) 2 and MIS 6/5e transition, and with peak SSTs of 22-23°C during early MIS 1 and MIS 5a/4, 5c/5b, and 5e/5d transitions. The SSTs varied in parallel with changing carbon isotope differences between Globorotalia inflata and Globigerina bulloides, which suggests that the SST changes were primarily caused by latitudinal displacements of the Kuroshio-Oyashio Currents. A strong correlation between the SST shifts and orbital forcing indicates that latitudinal displacements of the Kuroshio-Oyashio Currents were influenced by summer insolation at 65°N.