969 resultados para Bellingshausen Sea, slope on TMF


Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Resumo:

At mid- to high-latitude marine sites, ice-rafted debris (IRD) is commonly recognized as anomalously coarse-grained terrigenous material contained within a fine-grained hemipelagic or pelagic matrix (e.g., Conolly and Ewing, 1970; Ruddiman, 1977, doi:10.1130/0016-7606(1977)88<1813:LQDOIS>2.0.CO;2; Krissek, 1989, doi:10.2973/odp.proc.sr.104.114.1989; Jansen et al., 1990; Bond et al., doi:10.1038/360245a0, 1992; Krissek, 1995, doi:10.2973/odp.proc.sr.145.118.1995). The presence of such ice-rafted material is a valuable indicator of the presence of glacial ice at sea level on an adjacent continent, whereas the composition of the IRD can often be used to identify the location of the source area (e.g., Goldschmidt, 1995, doi:10.1016/0025-3227(95)00098-J). Because the amount of core recovered during Leg 163 was very limited, this shore-based, postcruise study focuses on materials recovered at a nearby site during Leg 152. In particular, this study examines sediments recovered at Site 919; these sediments were described as containing a significant ice-rafted component in the Leg 152 Initial Reports volume (Larsen, Saunders, Clift, et al., 1994, doi:10.2973/odp.proc.ir.152.1994). In this study, the sedimentary section from Site 919 has been examined with the goal of providing a detailed history of glaciations on Greenland and other landmasses adjacent to the Norwegian-Greenland Sea; this history ultimately will be calibrated using an oxygen isotope stratigraphy (Flower, 1998, doi:10.2973/odp.proc.sr.152.219.1998), although that calibration has not been completed at this time. Because ice-core studies of the Greenland Ice Sheet (GIS) have shown that the GIS changed dramatically, and in some cases extremely rapidly, during at least the last interglacial stage (GRIP Members, 1993, doi:10.1038/364203a0), a detailed IRD record from the Southeast Greenland margin should provide insight into the longer term behavior of this sensitive component of the Northern Hemisphere climate system.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A collection of miscellaneous pamphlets.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

On verso of t.-p.: Authorized edition.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Printing date varies on extra copies.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We provide a reconstruction of atmospheric CO2 from deep-sea sediments, for the past 625000 years (Milankovitch chron). Our database consists of a Milankovitch template of sea-level variation in combination with a unique data set for the deep-sea record for Ontong Java plateau in the western equatorial Pacific. We redate the Vostok ice-core data of Barnola et al. (1987, doi:10.1038/329408a0). To make the reconstructions we employ multiple regression between deep-sea data, on one hand, and ice-core CO2 data in Antarctica, on the other. The patterns of correlation suggest that the main factors controlling atmospheric CO2 can be described as a combination of sea-level state and sea-level change. For best results squared values of state and change are used. The square-of-sea-level rule agrees with the concept that shelf processes are important modulators of atmospheric CO2 (e.g., budgets of shelf organic carbon and shelf carbonate, nitrate reduction). The square-of-change rule implies that, on short timescales, any major disturbance of the system results in a temporary rise in atmospheric CO2.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Boussinesq equation appears as the zeroth-order term in the shallow water flow expansion of the non-linear equation describing the flow of fluid in an unconfined aquifer. One-dimensional models based on the Boussinesq equation have been used to analyse tide-induced water table fluctuations in coastal aquifers. Previous analytical solutions for a sloping beach are based on the perturbation parameter, epsilon(N) = alphaepsilon cot beta (in which beta is the beach slope, alpha is the amplitude parameter and epsilon is the shallow water parameter) and are limited to tan(-1) (alphaepsilon) much less than beta less than or equal to pi/2. In this paper, a new higher-order solution to the non-linear boundary value problem is derived. The results demonstrate the significant influence of the higher-order components and beach slope on the water table fluctuations. The relative difference between the linear solution and the present solution increases as 6 and a increase, and reaches 7% of the linear solution. (C) 2003 Elsevier Ltd. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Exclusive Fishing Zones (EFZs) are a type of place-based management tool often used to mitigate conflicts between fishing sectors by granting fishing rights to one of the sectors. This case study enhances our knowledge of the pre- and post-implementation processes associated with EFZs as well as its consequences for fish stocks and artisanal fishers and their families. The study draws upon interviews with artisanal fishers and key informants related to an EFZ established in 2008 in Colombia (the Chocó-EFZ). The findings of this research indicate that conflicts at sea and on land between artisanal and industrial fisheries triggered the Chocó-EFZ process. Results also show some potential benefits of the Chocó-EFZ including: a) mitigating conflicts between artisanal fishers and industrial shrimpers; b) contributing to the food security of artisanal fishing households and sustaining local fish stocks; c) supporting an existing informal community-based management as well as promoting the development of a co-management regime. Potential negative effects of the Chocó-EFZ include: a) displacement of industrial fishing effort and, b) job loss within the industrial shrimp industry. The findings of this research also indicate that there are multiple factors that jeopardize the effectiveness and continuation of the Chocó-EFZ, some of which include diversity of fisheries, power struggles among stakeholders, and disagreement about exclusive access to fish resources.

Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Dickson Land peninsula is located in central West-Spitsbergen between the NNE branches of Isfjorden. The climatic firn line lying at 500 m causes plateau glaciers with outlet tongues which are characteristic of S-Dickson Land. The distribution of valley glaciers and the variations of the orographic firn line depend on wind direction. In comparing the firn lines established by the methods of LICHTENECKER (1938) and VISSER (1938), to the values calculated by the method of v. HÖFER (1879), differences of up to l07 m are found. These differences may depend on the inclination and distance relationships of the glaciers above and below the real firn lines. During the latest glacial advance, Dickson Land was located on the peripheries of two local glaciation centers. At that time an inland glaciation of West-Spitsbergen did not exist . The formation of a subglacial channel system dates back to the maximum extent of the late glacial phase before 17500 B.P, (+2000/-1375 years). A correlation of postglacial stadia and 14C dated marine terraces (FEYLING-HANSSEN & OLSSON, 1960; FEYLING-HANSSEN, 1965) is possible. Considering isostatic movement and the difference between calculated and real firn lines, a postglacial stadium at about 10400 B. P. can be reconstructed with a firn line lying 265 m above former sea level. On average, the absolute depression below the recent firn line amounted to 246 m. Stagnation at 9650 B.P. coincided with a firn line at 315 m above former sea level and a depression of 173 m. Around 1890 A.D., glacial fluctuations corresponded to a firn line at 415 m (depression: 64 m). To some extent the morphology of the main valleys appears to depend on structure and petrography. Therefore their value as indicators of former glaciations is questionable. The periglacial forms are shown on a large-scale map. At the time of the "Holocene warm interval", between 7000 and 2000 B.P. (FEYLING-HANSSEN, 1955a, 1965), an increase of periglacial activity seems likely. This can be explained by a simultaneous increase in the depth of the active layer in both soil and bedrock.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A partir de los grabados publicados en las páginas de los periódicos que incluyeron humor gráfico en sus ediciones durante la Guerra del Pacífico (1879 - 1883), los caricaturistas chilenos desplegaron un discurso visual agresivo en clave patriótica y belicista, donde presentaron a sus lectores una imagen crítica y despectiva respecto de los adversarios de Chile. Recalcaron la supuesta falta de ánimo y valor combativo, ante la sola presencia de los efectivos militares chilenos tanto en el mar como en tierra. Así, la tinta y el papel, se transformaron en otra de las armas que intervinieron en el conflicto de Chile contra el Perú y Bolivia por la posesión de los ricos territorios salitreros de Tarapacá y Antofagasta. Las imágenes fueron interpretadas a partir de los postulados de la Escuela de Warburg, en especial los de Erwin Panofsky, que propone tres niveles de estudio del significado de cada obra, a saber, la “descripción preiconográfica”, luego el “estudio iconográfico” en cuanto tal y, finalmente, la “interpretación iconológica”.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Controversy over the alpine route that Hannibal of Carthage followed from the Rhône Basin into Italia has raged amongst classicists and ancient historians for over two millennia. The motivation for identifying the route taken by the Punic Army through the Alps lies in its potential for identifying sites of historical archaeological significance and for the resolution of one of history's most enduring quandaries. Here, we present stratigraphic, geochemical and microbiological evidence recovered from an alluvial floodplain mire located below the Col de la Traversette (~3000 m asl-above sea level) on the French/Italian border that potentially identifies the invasion route as the one originally proposed by Sir Gavin de Beer (de Beer 1974). The dated layer is termed the MAD bed (mass animal deposition) based on disrupted bedding, greatly increased organic carbon and key/specialized biological components/compounds, the latter reported in Part II of this paper. We propose that the highly abnormal churned up (bioturbated) bed was contaminated by the passage of Hannibal's animals, possibly thousands, feeding and watering at the site, during the early stage of Hannibal's invasion of Italia (218 bc).

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Suomi luopui puolueettomuuspolitiikasta turvallisuuspoliittisena linjanaan kun se liittyi Euroopan unioniin ennen kaikkea turvallisuussyistä. Vaikka Suomi on EU-jäsenyyden myötä poliittisesti liittoutunut ja vaikka se on jatkuvasti laajentanut ja syventänyt yhteistyötään NATOn kanssa, Suomi on yhä sotilaallisesti liittoutumaton valtio. Suomen turvallisuuspoliittinen toimintaympäristö on ollut poikkeuksellisen vakaa kylmän sodan jälkeen ennen kaikkea siksi, että maailman voimakkain suurvalta Yhdysvallat on yhä sotilaallisesti läsnä Euroopassa ja Euroopan integraatio on jatkunut ja syventynyt. Suomi on sitonut nykyisen turvallisuuspoliittisen linjansa turvallisuusympäristönsä pysyvyyteen. Viime vuosina NATOn laajentuminen entisen Neuvostoliiton alueelle on voimistanut läntisten suurvaltojen ja Venäjän välistä valtakamppailua ja turvallisuuskilpailua Suomen lähialueella. Viimeistään Ukrainan konflikti on tehnyt ajankohtaiseksi myös kysymyksen Suomen sotilaallisesta liittoutumisesta. Tässä artikkeliteoksessa turvallisuuspolitiikan asiantuntijat analysoivat keskeisimpien ulkoisten toimijoiden – EU:n, Ruotsin, Viron, Venäjän, Yhdysvaltojen ja NATOn – merkitystä Suomen turvallisuuspoliittisen toimintaympäristön vakaudelle ja Suomen turvallisuudelle sekä pohtivat, onko Suomen syytä muuttaa nykyistä turvallisuuspoliittista linjaansa turvallisuusympäristössä tapahtuneiden muutosten vuoksi. Kirjoittajat myös arvioivat Suomen mahdolliseen sotilaalliseen liittoutumiseen liittyviä etuja ja haittoja verrattuna nykyiseen turvallisuuspoliittiseen ratkaisuun. Teoksen kirjoittajien toisistaan poikkeavat näkemykset Suomen turvallisuuspoliittisen toimintaympäristön vakaudesta, NATOn laajentumisen vaikutuksista Itämeren alueella, Venäjän valtapolitiikasta ja sen Suomelle muodostaman sotilaallisen uhan voimakkuudesta, NATOn pelotteen uskottavuudesta ja Yhdysvaltojen sitoutumisesta liittolaistensa puolustamiseen sekä Suomen NATO-jäsenyyden eduista ja haitoista valaisevat laajasti kysymystä Suomen turvallisuudesta ja turvallisuuspoliittisesta ratkaisusta. Suomelle sen geopoliittinen asema Venäjälle strategisesti elintärkeiden Kuolan alueen ja Pietari–Moskova-ydinalueen välittömässä läheisyydessä on ongelmallinen maan turvallisuuden kannalta. Suurvalta Venäjä onkin edelleen keskeisin Suomen turvallisuuteen ja turvallisuuspoliittiseen ratkaisuun vaikuttava ulkoinen toimija. Neuvostoliiton hajoamisen jälkeen Suomella on ollut ainutlaatuinen mahdollisuus liittoutua Yhdysvaltojen kanssa NATO-jäsenyyden myötä Venäjän potentiaalista sotilaallista uhkaa vastaan. Toisaalta Suomella ei kuitenkaan ole ollut pakottavaa tarvetta siihen, koska se on välillisesti hyötynyt Yhdysvaltojen suurstrategiasta Euroopassa ja koska Venäjän valtapolitiikka on kohdistunut ennen kaikkea entisen Neuvostoliiton alueelle. Vaikka Ukrainan konflikti onkin lisännyt poliittista ja sotilaallista jännitettä Itämeren alueella, tämän teoksen perusteella on kuitenkin mahdotonta antaa yksiselitteistä vastausta siihen, pitäisikö Suomen sen turvallisuuspoliittisessa toimintaympäristössä tapahtuneen muutoksen seurauksena liittyä NATOn jäseneksi vai ei. Halutessaan Suomi voi siis edelleen jatkaa nykyisellä turvallisuuspoliittisella linjallaan sotilaallisesti liittoutumattomana valtiona, mutta samalla sen täytyy kuitenkin pitää myös sotilaallinen liittoutuminen avoimena turvallisuuspoliittisena vaihtoehtona tulevaisuudessa.