981 resultados para Thompson, James William, 1805-1881.
Resumo:
by Sarah Harvey Porter.
Resumo:
The middle Miocene Climatic Optimum (17-15 Ma; MCO) is a period of global warmth and relatively high CO2 and is thought to be associated with a significant retreat of the Antarctic Ice Sheet (AIS). We present here a new planktic foraminiferal d11B record from 16.6 to 11.8 Ma from two deep ocean sites currently in equilibrium with the atmosphere with respect to CO2. These new data demonstrate that the evolution of global climate during the middle Miocene (as reflected by changes in the cyrosphere) was well correlated to variations in the concentration of atmospheric CO2. What is more, within our sampling resolution (~1 sample per 300 kyr) there is no evidence of hysteresis in the response of ice volume to CO2 forcing during the middle Miocene, contrary to what is understood about the Antarctic Ice Sheet from ice sheet modelling studies. In agreement with previous data, we show that absolute levels of CO2 during the MCO were relatively modest (350-400 ppm) and levels either side of the MCO are similar or lower than the pre-industrial (200-260 ppm). These new data imply the presence of either a very dynamic AIS at relatively low CO2 during the middle Miocene or the advance and retreat of significant northern hemisphere ice. Recent drilling on the Antarctic margin and shore based studies indicate significant retreat and advance beyond the modern limits of the AIS did occur during the middle Miocene, but the complete loss of the AIS was unlikely. Consequently, it seems that ice volume and climate variations during the middle Miocene probably involved a more dynamic AIS than the modern but also some component of land-based ice in the northern hemisphere.
Resumo:
14x10 cm. engraving. Engraved for Bernard's American journal of education/
Resumo:
On mount: Courthouse Square-Ann Arbor. On verso: Sunday April 15, 1861. News of the war. Meeting called at Court House square by Dr. Tappan. News that [Fort] Sumter was fired upon. Property of Ellen B. Bach
Resumo:
"Reference to illustrations of plants other than those figured in this work" precedes text in each volume.
Resumo:
"April 1980"--Cover.
Resumo:
Mode of access: Internet.
Resumo:
Mode of access: Internet.
Resumo:
In original paper wrappers.
Resumo:
A corrupted labor leadership.--Class collaboration.--Reactionary labor politics.--Bribery and betrayal in various industries.--Organized graft in the building trades.--Plundering the workers.Trade union capitalism swindle.--Tainted labor journalism.--Autocratic control of the unions.--What must be done.
Resumo:
Mode of access: Internet.
Resumo:
"Entered, according to Act of Congress, in the year 1854, by Lindsay & Blakiston ... Stereotyped by J. Fagan, printed by C. Sherman, plates printed by T. Sinclair"--Verso of title page.