America settentrionale divisa ne' suoi principali stati.

Scale ca. 1:21,500,000.

Response of Pacific Northwest vegetation to large-scale changes in climate during the last 100,000 years [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Paleoclimatic variations in western North America depend on a hierarchy of temporal and spatial controls that can be examined using a combination of modeling studies and data synthesis. ... The regional vegetation response to large-scale changes in the climate system of the last 21,000 years is used as a conceptual model to help explain earlier vegetation and climate at two localities.

Gravity mapping in the southern Weddell Sea region, Antarctica (Scale 1:2 000 000)

New maps of free-air and the Bouguer gravity anomalies on the Weddell Sea sector (70-81° S, 6-75° W) of Antarctica are presented. These maps are based on the first computer compilation of available gravity data collected by ''Sevmorgeologia'' in 1976-89 in the southern Weddell Sea and adjacent coasts of western Dronning Maud Land (WDML) and Coats Land. The accomplished gravity studies comprise airborne observations with a line spacing of about 20 km and conventional measurements at over-the-ice points, which were spaced at 10-30 km and supplemented by seismic soundings. Hence, anomalies on the maps represent mainly large-scale and deep crustal features. The dominant feature in free-air gravity map is a large dipolar gravity anomaly stretching along the continental margin. Following the major grain of seabed morphology this shelf-edge/slope anomaly (SESA) is clearly divided into three segments characterized by diverse anomaly amplitudes, wavelengths and trends. They are associated with continental margins of different geotectonic provinces of Antarctica surrounding the Weddell Sea. Apparent distinctions in the SESA signatures are interpreted as the gravity expression of tectonic, deep crustal structure segmentation of the continental margin. The prominent gravity highs (100-140 mGal) of the shelf edge anomaly mapped along WDML are assumed to represent high-density mantle injections intruded into the middle/lower crust during initial rifting of continental breakup. Enlarged wavelengths and diminished amplitudes of the gravity anomaly westwards, along the Weddell Sea embayment (WSE) margin, reflect a widening of the continental slope and a significant increase in thickness of underlying sediment strata. Low amplitude, negative free-air anomalies in the Filchner-Ronne Ice Shelves (FRIS) contrast sharply with the dominating positive anomalies offshore. This indicates a greater sedimentary thickness of the basin in this area. Crustal response to the enlarged sediment load is impressed in mostly positive features of the Bouguer gravity field observed here. Two pronounced positive Bouguer anomalies of 50-70 mGal and an average widths of 200 km dominate the Weddell Sea embayment margins towards the Antarctic Peninsula and the East Antarctic craton. They correlate well with very deep seabed troughs (> 1000 m below sea level). The gravity highs are most likely caused by a shallow upper mantle underneath graben-rift structures evolved at the margins of the WSE basin. A regional zone (> 100 km in width) of the prominent Bouguer and free-air negative anomalies (-40 to -60 mGal) adjacent Coats Land to the north of the ice shelf edge may indicate the presence of the thick old cratonic crust far offshore beneath the Weddell Sea Embayment.

Bergen op Zoom, Netherlands, ca. 1747 (Image 1 of 2) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Plan de la forte ville de Berguen op den Zoom avec ses lignes, attaques, et le Fort Steenberguen, desinè par Albert d'Herbort, Ingenieur. It was published by publié par Matthieu Seutter, Geogr. Imperial ca. 1747. Scale [ca. 1:20,000]. Covers Bergen op Zoom, Netherlands. This layer is image 1 of 2 total images of the two sheet source map, representing the southern portion of the map. Map in French. The image inside the map neatline is georeferenced to the surface of the earth and fit to the RD_New (Rijksdriehoekstelsel), GCS Amersfoort coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, roads, villages and other human settlements, fortifications, lines of fire, ground cover, and more. Relief shown pictorially and by hachures. Includes index.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.