 |
| Titel |
Candidates for multiple impact craters?: Popigai and Chicxulub as seen by the global high resolution gravitational field model EGM2008 |
| VerfasserIn |
J. Klokočník, J. Kostelecký, I. Pešek, P. Novák, C. A. Wagner, J. Sebera |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1869-9510
|
| Digitales Dokument |
URL |
| Erschienen |
In: Solid Earth ; 1, no. 1 ; Nr. 1, no. 1 (2010-07-21), S.71-83 |
| Datensatznummer |
250000119
|
| Publikation (Nr.) |
 copernicus.org/se-1-71-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
| In 2008 the new Earth Gravitational Model (EGM2008) was released. It
contains a complete set of spherical harmonic coefficients of the Earth's
gravitational potential (Stokes parameters) to degree 2190 and order 2159
and selected orders to degree 2190, that can be used for evaluation of
various potential quantities with both the unprecedented accuracy and high
spatial resolution. Two such quantities, the gravity anomaly and
second-order radial derivative of the disturbing potential, were computed
over selected areas with known impact craters. The displays of these
derivatives for two such sites clearly show not only the strong
circular-like features known to be associated with them but also other
symmetrical structures which appear to make them multiple impact sites. At
Popigai, Siberia, the series of circular features fall in a line from the
"primary crater" in the southeast (SE) direction. At Chicxulub,
Yucatán, there appears to be one more crater close to the "primary" in
the northeast (NE) direction, as well as possibly others in the vicinity of
the main crater (SW). Gravity information alone is not, however, proof of
impact craters but it is useful in identifying candidate sites for further study, for
examination by geologists and geophysicists. In the case of Chicxulub, a
very recent single seismic profile suggests that a more likely explanation
for the observed circular like gravity signal from EGM2008 NE of the
"primary" is a pre-impact basin. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|