Stable Isotope and Lithologic Evidence of Late-Glacial and Holocene Oceanography of the Northwestern Pacific and Its Marginal Seas

1996 ◽  
Vol 46 (3) ◽  
pp. 230-250 ◽  
Author(s):  
Sergei A. Gorbarenko
Keyword(s):  
Bering Sea ◽  
Planktonic Foraminifera ◽  
Late Glacial ◽  
Northwestern Pacific ◽  
Intermediate Water ◽  
Regional Environment ◽  
The Holocene ◽  
Marginal Seas ◽  
The North ◽  
The Bering Sea

Stable isotopes, geochemical, lithological, and micropaleontological results from cores from the far northwest (FNW) Pacific and the Okhotsk and Bering seas are used to reconstruct the regional environment for the last glaciation, the deglacial transition, and the Holocene. δ18O records of planktonic foraminifera of the region show two “light” shifts during deglacial time, provoked by the freshening of the surface water and climate warming. These north Pacific terminal events (T1ANP and T1BNP) with ages of 12,500 and 9300 yr B.P., respectively, occur almost simultaneously with two episodes of accelerated glacier melting around the North Atlantic. Along with the isotopic shifts, the CaCO3 content in regional sediments increased abruptly (1A and 1B carbonate peaks), probably due to changes of productivity and pore water chemistry of surface sediments. Organic matter and opal concentration increased during the transition (between T1ANP and T1BNP events) in the sediments of the FNW Pacific and the southern part of the Bering Sea and opal content increased in the Holocene in the Bering and Okhotsk Seas. δ13C records of cores from the Okhotsk and Bering seas and the FNW Pacific do not contradict the hypothesis of increased intermediate water formation in the region during glaciation. During deglaciation, accumulation of the coarse terrigenous component decreased in sediments of the Bering Sea and the FNW Pacific before the T1ANP event, probably as a result of rising sea level and opening of the Bering Strait.

Diatom Evidence on Wisconsin and Holocene Events in the Bering Sea

1983 ◽  
Vol 20 (2) ◽  
pp. 232-245 ◽  
Author(s):  
Constance Sancetta ◽  
Stephen W. Robinson
Keyword(s):  
Sea Ice ◽  
Bering Sea ◽  
North Pacific Ocean ◽  
Ice Cover ◽  
Phytoplankton Productivity ◽  
Cool Period ◽  
Marginal Seas ◽  
The North ◽  
Ocean Environment ◽  
The Bering Sea

Previous work on surface (modern) sediments has defined diatom species which appear to be good indicators of various oceanographic/ecologic conditions in the North Pacific Ocean and marginal seas. Three long cores from the eastern and northern sides of the Aleutian Basin show changes in species assemblage which can be interpreted in terms of changes in the ocean environment during the last glaciation (Wisconsin) and the Holocene. The early and late Wisconsin maxima were times of prolonged annual sea-ice cover and a short cool period of phytoplankton productivity during the ice-free season. The middle Wisconsin interstade, at least in the southern Bering Sea, had greater seasonal contrast than today, with some winter sea-ice cover, an intensified temperature minimum, and high spring productivity. Variations in clastic and reworked fossil material imply varying degrees of transport to the basin by Alaskan rivers. The results of Jousé from the central Bering Sea generally correspond with those presented here, although there are problems with direct comparison.

scholarly journals Steller’s sea cow genome suggests this species began going extinct before the arrival of Paleolithic humans

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Fedor S. Sharko ◽  
Eugenia S. Boulygina ◽  
Svetlana V. Tsygankova ◽  
Natalia V. Slobodova ◽  
Dmitry A. Alekseev ◽  
...  
Keyword(s):  
Bering Sea ◽  
De Novo ◽  
Anthropogenic Activity ◽  
Commander Islands ◽  
The North ◽  
Extinction Process ◽  
Sea Cow ◽  
The North Pacific ◽  
The Bering Sea ◽  
Woolly Mammoth

AbstractAnthropogenic activity is the top factor directly related to the extinction of several animal species. The last Steller’s sea cow (Hydrodamalis gigas) population on the Commander Islands (Russia) was wiped out in the second half of the 18th century due to sailors and fur traders hunting it for the meat and fat. However, new data suggests that the extinction process of this species began much earlier. Here, we present a nuclear de novo assembled genome of H. gigas with a 25.4× depth coverage. Our results demonstrate that the heterozygosity of the last population of this animal is low and comparable to the last woolly mammoth population that inhabited Wrangel Island 4000 years ago. Besides, as a matter of consideration, our findings also demonstrate that the extinction of this marine mammal starts along the North Pacific coastal line much earlier than the first Paleolithic humans arrived in the Bering sea region.

scholarly journals Millennial-scale climate change and intermediate water circulation in the Bering Sea from 90 ka: A high-resolution record from IODP Site U1340

2013 ◽  
Vol 28 (1) ◽  
pp. 54-67 ◽  
Author(s):  
Shiloh A. Schlung ◽  
A. Christina Ravelo ◽  
Ivano W. Aiello ◽  
Dyke H. Andreasen ◽  
Mea S. Cook ◽  
...  
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Bering Sea ◽  
Water Circulation ◽  
Intermediate Water ◽  
The Bering Sea ◽  
Site U1340 ◽  
Millennial Scale

Holocene and latest Pleistocene fluctuations of Stutfield Glacier, Canadian Rockies

2001 ◽  
Vol 38 (8) ◽  
pp. 1141-1155 ◽  
Author(s):  
G D Osborn ◽  
B J Robinson ◽  
B H Luckman
Keyword(s):  
19Th Century ◽  
18Th Century ◽  
Late Glacial ◽  
Ice Age ◽  
Late 19Th Century ◽  
Canadian Rockies ◽  
The Holocene ◽  
The North ◽  
History Of ◽  
Glacier Advance

The Holocene and late glacial history of fluctuations of Stutfield Glacier are reconstructed using moraine stratigraphy, tephrochronology, and dendroglaciology. Stratigraphic sections in the lateral moraines contain tills from at least three glacier advances separated by volcanic tephras and paleosols. The oldest, pre-Mazama till is correlated with the Crowfoot Advance (dated elsewhere to be Younger Dryas equivalent). A Neoglacial till is found between the Mazama tephra and a paleosol developed on the Bridge River tephra. A log dating 2400 BP from the upper part of this till indicates that this glacier advance, correlated with the Peyto Advance, culminated shortly before deposition of the Bridge River tephra. Radiocarbon and tree-ring dates from overridden trees exposed in moraine sections indicate that the initial Cavell (Little Ice Age (LIA)) Advance overrode this paleosol and trees after A.D. 1271. Three subsequent phases of the Cavell Advance were dated by dendrochronology. The maximum glacier extent occurred in the mid-18th century, predating 1743 on the southern lateral, although ice still occupied and tilted a tree on the north lateral in 1758. Subsequent glacier advances occurred ca. 1800–1816 and in the late 19th century. The relative extent of the LIA advances at Stutfield differs from that of other major eastward flowing outlets of the Columbia Icefield, which have maxima in the mid–late 19th century. This is the first study from the Canadian Rockies to demonstrate that the large, morphologically simple, lateral moraines defining the LIA glacier limits are actually composite features, built up progressively (but discontinuously) over the Holocene and contain evidence of multiple Holocene- and Crowfoot-age glacier advances.

Nonrandom distribution of chum salmon stocks in the Bering Sea and the North Pacific Ocean estimated using mitochondrial DNA microarray

2009 ◽  
Vol 75 (2) ◽  
pp. 359-367 ◽  
Author(s):  
Shogo Moriya ◽  
Shunpei Sato ◽  
Moongeun Yoon ◽  
Tomonori Azumaya ◽  
Shigehiko Urawa ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Dna Microarray ◽  
Bering Sea ◽  
North Pacific ◽  
Chum Salmon ◽  
North Pacific Ocean ◽  
The North ◽  
Nonrandom Distribution ◽  
The North Pacific ◽  
The Bering Sea

scholarly journals ВИХРЕВАЯ СТРУКТУРА ВОСТОЧНО-КАМЧАТСКОГО ТЕЧЕНИЯ ПО СПУТНИКОВЫМ НАБЛЮДЕНИЯМ

2019 ◽  
Author(s):  
N.M. Vakulskaya ◽  
V.A. Dubina ◽  
V.V. Plotnikov
Keyword(s):  
Bering Sea ◽  
Life Time ◽  
Winter Monsoon ◽  
Synoptic Scale ◽  
The North ◽  
Kamchatka Current ◽  
North And South ◽  
Multisensor Data ◽  
Mesoscale Cyclones ◽  
The Bering Sea

На основе анализа архива спутниковых мультисенсорных данных исследована динамика ледяного покрова в области ВосточноКамчатского течения. При развитом зимнем муссоне плавучий лёд смещается вдоль побережья Камчатки на юг, трассируя разномасштабные вихри, которые возникают при взаимодействии потока ВосточноКамчатского течения с неоднородностями береговой черты и континентального склона. Средняя скорость дрейфа, рассчитанная по изображениям, полученным в марте 2016 г. в один день с разницей в 110 мин, составила 0,25 м/с, что в два с половиной раза превысило суточное значение. На севере и на юге района значения скорости дрейфа превышали скорости в центральной части. При ослаблении зимнего муссона в поле дрейфующего льда в западной части Берингова моря образуются хорошо выраженные грибовидные структуры, горизонтальные размеры которых могут превышать 200 км. Наряду с известными ранее синоптическими вихревыми образованиями синоптического масштаба спутниковые данные высокого (10 15 м) и среднего (250 м) пространственного разрешения позволили зарегистрировать многочисленные мезомасштабные циклоны диаметром 10 25 км и временем жизни от 1 до 14 суток.On the basis of the analysis of the satellite multisensor data archive, the dynamics of the ice cover in the region of the East Kamchatka Current is investigated. With the developed winter monsoon, floating ice shifts along the Kamchatka coast to the south, tracing the multiscale eddies that appear when the East Kamchatka stream interacts with the inhomogeneities of the coastline and the continental slope. The average drift speed calculated from images taken in March 2016 on the same day with a difference of 110 min was 0.25 m / s, which was two and a half times higher than the daily value. On the north and south of the region, the drift velocity values exceeded the velocities in the central part. With the attenuation of the winter monsoon in the field of drifting ice in the western part of the Bering Sea, welldefined mushroomlike structures are formed, the horizontal dimensions of which can exceed 200 km. Together previously known synoptic eddy formations of a synoptic scale, satellite data of high (10 15 m) and moderate (250 m) spatial resolution made it possible to register numerous mesoscale cyclones with a diameter of 10 25 km and a life time of 1 to 14 days.

scholarly journals Feeding of smoothtongue Leuroglossus schmidti in the Bering, Okhotsk Seas and adjacent waters of the Pacific Ocean

2016 ◽  
Vol 184 (1) ◽  
pp. 150-157
Author(s):  
Alexander Ya. Efimkin
Keyword(s):  
Bering Sea ◽  
Mesopelagic Fish ◽  
The North ◽  
Important Prey ◽  
The Pacific ◽  
Upper Epipelagic Layer ◽  
The Pacific Ocean ◽  
The North Pacific ◽  
Epipelagic Layer ◽  
The Bering Sea

Smoothtongue Leuroglossus schmidti is a small mesopelagic fish species common for subarctic waters. It rises to the upper epipelagic layer at night for feeding and preys mainly on euphausiids, copepods and amphipods. Its mean index of stomach fullness reaches 68 ‱ in the epipelagic layer, but it almost doesn’t feed deeper than 200 m, judging by a little food in the stomach. In the Bering Sea, euphausiids dominate in its diet and the portion of copepods is small. In the ​​Okhotsk Sea, each of these two groups provides a half of the diet. In the North Pacific, the portion of copepods is 63 % on average, euphausiids are the second important prey, and amphipods occur in the diet occasionally. Daily ration of smoothtongue is about 1.4 %.

scholarly journals Feeding of adult sea bream Brama japonica in the Pacific Ocean and the Bering Sea

2014 ◽  
Vol 176 (1) ◽  
pp. 210-215
Author(s):  
Alexander Ya. Efimkin
Keyword(s):  
Bering Sea ◽  
Feeding Habits ◽  
Sea Bream ◽  
Daily Ration ◽  
The North ◽  
The Pacific ◽  
The Pacific Ocean ◽  
High Concentrations ◽  
The North Pacific ◽  
The Bering Sea

Feeding habits of adult sea bream are considered on the samples collected in the North Pacific and Bering Sea in the last several years. This species is a predator with the diet highly dependent on its habitat and composition of prey (small-sized fish and squids). It has two or three peaks of consumption daily, which change seasonally and year-to-year; anyway, the morning (3-6 a.m.) is usually the time of the lowest consumption, at least in summer and autumn, and the daytime is the normal time for feeding. The sea bream does not eat zooplankton usually, but Euphausia pacifica was a significant portion of its diet (34 %) in the southern part of surveyed area in the summer of 2009, possibly because of high concentrations of euphausiids in that area. Daily ration of adult sea bream is 2.5-3.5 % of its body weight.

Sign in / Sign up

Export Citation Format

Share Document