Search results
Results from the WOW.Com Content Network
[7] [8] [9] However, the lack of corroborating evidence of a causal link between the Laschamp event and population bottlenecks of many megafauna species, and the relatively moderate radio-isotopic changes during the event, have cast significant doubt on the real impact of the Laschamp event on global environmental changes. [10]
The geographic poles are defined by the points on the surface of Earth that are intersected by the axis of rotation. The pole shift hypothesis describes a change in location of these poles with respect to the underlying surface – a phenomenon distinct from the changes in axial orientation with respect to the plane of the ecliptic that are caused by precession and nutation, and is an ...
NPOESS was a tri-agency program led by an Integrated Program Office (IPO) containing staff from the US Department of Defense, National Oceanic and Atmospheric Administration, and NASA. [1] NPOESS was to be operated by the NOAA/ National Environmental Satellite, Data, and Information Service (NESDIS) / NPOESS Program Executive Office Flight ...
In the early 20th century, geologists such as Bernard Brunhes first noticed that some volcanic rocks were magnetized opposite to the direction of the local Earth's field. . The first systematic evidence for and time-scale estimate of the magnetic reversals were made by Motonori Matuyama in the late 1920s; he observed that rocks with reversed fields were all of early Pleistocene age or old
The program selects medium-class missions which can provide high science returns. NASA is encouraging both domestic and international scientists to submit mission proposals for the program. [3] New Frontiers was built on the innovative approach used by the Discovery and Explorer Programs of principal investigator-led missions.
In all, 38 Discoverer satellites were launched by February 1962, although the satellite reconnaissance program continued until 1972 as the CORONA project. The program documents were declassified in 1995. [3] Discoverer 1 was a test of the performance capabilities of the propulsion and guidance system of the booster and satellite.
Polar drift is a geological phenomenon caused by variations in the flow of molten iron in Earth's outer core, resulting in changes in the orientation of Earth's magnetic field, and hence the position of the magnetic north- and south poles. The North magnetic pole is approximately 965 kilometres (600 mi) from the geographic North Pole. The pole ...
A geomagnetic excursion, like a geomagnetic reversal, is a significant change in the Earth's magnetic field.Unlike reversals, an excursion is not a long-term re-orientation of the large-scale field, but rather represents a dramatic, typically a (geologically) short-lived change in field intensity, with a variation in pole orientation of up to 45° from the previous position.