Titre du document / Document title

Episodic plate separation and fracture infill on the surface of Europa

Auteur(s) / Author(s)

Galileo Imaging Team
SULLIVAN R. ⁽¹⁾ ; GREELEY R. ⁽¹⁾ ; HOMAN K. ⁽¹⁾ ; KLEMASZEWSKI J. ⁽¹⁾ ; BELTON M. J. S. ⁽²⁾ ; CARR M. H. ⁽³⁾ ; CHAPMAN C. R. ⁽⁴⁾ ; TUFTS R. ⁽⁵⁾ ; HEAD J. W. ⁽⁶⁾ ; PAPPALARDO R. ⁽⁶⁾ ; MOORE J. ⁽⁷⁾ ; THOMAS P. ⁽⁸⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Department of Geology, Box 871404, Arizona State University Tempe, Arizona 85287-1404, ETATS-UNIS
⁽²⁾ National Optical Astronomy Observatory, Tucson, Arizona 85719, ETATS-UNIS
⁽³⁾ US Geological Survey, Menlo Park, California 94025, ETATS-UNIS
⁽⁴⁾ Southwest Research Institute, Boulder, Colorado 8032, ETATS-UNIS
⁽⁵⁾ Lunar and Planetary Laboratory, University of Arizona, Tucsun, Arizona 85721, ETATS-UNIS
⁽⁶⁾ Department of Geological Sciences, Brown University, Providence, Rhode Island 02912, ETATS-UNIS
⁽⁷⁾ Ames Research Center, Moffett Field, California 94035, ETATS-UNIS
⁽⁸⁾ Cornell University, Ithaca, New York 14853, ETATS-UNIS

Résumé / Abstract

Images obtained by the Voyager spacecraft revealed dark, wedgeshaped bands on Europa that were interpreted as evidence that surface plates, 50-100km across, moved and rotated relative to each other¹. This implied that they may be mechanically decoupled from the interior by a layer of warm ice or liquid water^2,3. Here we report similar features seen in higher resolution images (420 metres per pixel) obtained by the Galileo spacecraft that reveal new details of wedge-band formation. In particular, the interior of one dark band shows bilateral symmetry of parallel lineaments and pit complexes which indicates that plate separation occurred in discrete episodes from a central axis. The images also show that this style of tectonic activity involved plates < 10 km across. Although this tectonic style superficially resembles aspects of similar activity on Earth, such as sea-floor spreading and the formation of ice leads in polar seas, there are significant differences in the underlying physical mechanisms: the wedge-shaped bands on Europa most probably formed when lower material (ice or water) rose to fill the fractures that widened in response to regional surface stresses.

Revue / Journal Title

Nature   ISSN 0028-0836   CODEN NATUAS 

Source / Source

1998, vol. 391, n^o6665, pp. 371-373 (13 ref.)

Langue / Language

Anglais

Editeur / Publisher

Nature Publishing, London, ROYAUME-UNI  (1869) (Revue)

Mots-clés anglais / English Keywords

Europa satellite ; fractures ; plate tectonics ; Voyager Program ; plate rotation ; decoupling ; ice ; water ; imagery ; high resolution ; lineaments ; tectogenesis ; terrestrial comparison ;

Mots-clés français / French Keywords

Satellite Europa ; Fracture ; Tectonique plaque ; Programme Voyager ; Rotation plaque ; Découplage ; Glace ; Eau ; Imagerie ; Haute résolution ; Linéament ; Tectogenèse ; Comparaison Terre ; Programme Galileo ;

Mots-clés espagnols / Spanish Keywords

Satélite Europa ; Fractura ; Tectónica placas ; Rotación placa ; Hielo ; Agua ; Imaginería ; Alta resolucion ; Lineamento ; Tectogénesis ; Comparación tierra ;

Localisation / Location

INIST-CNRS, Cote INIST : 142, 35400007767503.0140