930 resultados para Twentieth century


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Estudio dendrocronológico de estructuras arbóreas en alta montaña mediterránea.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The relation between changes in modern glaciers, not including the ice sheets of Greenland and Antarctica, and their climatic environment is investigated to shed light on paleoglacier evidence of past climate change and for projecting the effects of future climate warming on cold regions of the world. Loss of glacier volume has been more or less continuous since the 19th century, but it is not a simple adjustment to the end of an “anomalous” Little Ice Age. We address the 1961–1997 period, which provides the most observational data on volume changes. These data show trends that are highly variable with time as well as within and between regions; trends in the Arctic are consistent with global averages but are quantitatively smaller. The averaged annual volume loss is 147 mm⋅yr−1 in water equivalent, totaling 3.7 × 103 km3 over 37 yr. The time series shows a shift during the mid-1970s, followed by more rapid loss of ice volume and further acceleration in the last decade; this is consistent with climatologic data. Perhaps most significant is an increase in annual accumulation along with an increase in melting; these produce a marked increase in the annual turnover or amplitude. The rise in air temperature suggested by the temperature sensitivities of glaciers in cold regions is somewhat greater than the global average temperature rise derived largely from low altitude gauges, and the warming is accelerating.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fil: Starcenbaum, Marcelo. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

One letter from Harris, the University Librarian, to President Everett, enclosed with a historical account of the Great Salt and its donor, Richard Harris, and sketches of the new engravings on the Great Salt, Stoughton Cup, and Browne Cup bearing donor names. Harris writes that he hopes to have his account of the Great Salt published in the Cambridge Chronicle and is gratified to hear of Everett’s plans to use an excerpt in his Commencement dinner speech. In a short note of reply, Everett writes that Harris’ account of the silver was "received with great favor" during the dinner.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Transcription of inventories of College silver completed by Harris in 1845 and 1852, as well as an undated list of silver.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fil: Starcenbaum, Marcelo. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Mode of access: Internet.