Piton de la Fournaise, La Reunion Island, France, Courtesy of

Pete Mouginis Mark, University of Hawaii at Manoa, Honolulu, Hawaii.

3-D view of the C1 approximant, after post-processing, obtained for the Piton de la Fournaise volcano from the Digital Elevation Model of Figure. The color scale represents the height of the topography, from 0 to 2.6~km. The image has been generated with no vertical exaggeration. The approximant has been evaluated on an evenly spaced grid comprising 200 x 200 points. No significant oscillations can be observed, even in the difficult regions of the model, which are mainly the two valleys, and also the caldera. In this example, we have discretized the spline using 15 x20 Bogner-Fox-Schmit finite elements, each having sixteen degrees of freedom.

Comparison between the isocontours obtained from the original dataset of the Digital Elevation Model (above or left ), and the isocontours of the C1 approximant after post-processing, as in the 3-D view.. The general agreement is excellent, and it is important to notice that no significant oscillations can be observed, even in the two steep valleys. The isocontours represent the height of the topography every 0.2~km. The color scale also indicates the height of the topography, from 0 to 2.6~km.