Subject: disloc input Date: Tue, 7 Sep 1999 17:27:48 -0800 From: "Jay W. Parker" To: haupt@npac.syr.edu CC: Andrea.Donnellan@jpl.nasa.gov, Kenneth.Hurst@jpl.nasa.gov, Gregory.Lyzenga@jpl.nasa.gov (Andrea, Ken, Greg: note I ask you a question in paragraph 8 below). Here's a sample disloc input with commentary: 0.0 0.0 0 10 -50. -50. -50 0. -50. 50. 0. 50. 0. 0. 0. -50. 50. 0. 50. -50. 50. 50. 5. 4. 0.0 0.0 0.0 1 12.0 45. 1 1 1. 1. 0. 10. 10. That is, origin_latitude origin_longitude generation_parameter number_of_requested_points x y (repeat "x y" number_of_requested_points times) x_coord y_coord strike fault_type depth dip lambda mu u1 u2 u3 length width Commentary: origin_latitude and origin_longitude allow for a realistic lat/lon coordinate system: these values give the origin, while the x,y values give offsets generation_parameter can be 0, as here, in which case the format is: "number_of_requested_points", then follows a list of that many "x y" pairs. This will be useful for the demo, as we'll want the displacement values at GPS sites. Alternately the generation_parameter can be set to 1, which implies a rectangular regular grid of points, on the surface, with "x y" pairs generated by the following line, supplied as "x[0] x_increment number_points_in_x y[0] y_increment number_points_in_y" values, interpreted in the obvious way. The x_coord and y_coord define the vertical projection of the lower-left-hand corner of the fault rectangle onto the surface as an offset from the origin_latitude and origin_longitude. The strike defines the orientation of the projection of the rectangular patch (top or bottom edge, it makes no difference), clockwise from north. The fault_type may be 0 for a point fault; we'll not support that for the demo. So fault_type will be "1", and the terms "length width" indicate the rectangle, while "depth" says how deep the reference point (the lower-left corner) is (its "-z" coordinate, since the surface is at z=0). "Dip" indicates the angle above horizontal (we are only supporting rectangles with horizontal top and bottom edges). The values "u1 u2 u3" say how it slips (the u1 and u2 are the defining parameters for a screw dislocation, in the strike-slip and thrust sense, respectively; u3 will not be used for our demo, but represents a crack-opening amount when positive). Lambda and mu are physical bulk constituitive properties; I presume we'll keep those fixed for the demo. Ken, Andrea, Greg: what values should be used for lambda, mu? Does it matter? The last two lines' format may be repeated to include more faults (the resulting dislocations/strains are presumed linear in the fault dislocations). All of this is described in the file disloc.ps, which includes diagrams for the geometry; I'm including another copy as an enclosure. Yet another discription was supposed to be printed by the code when invoked without arguments; I see there is a path problem there. If desired, that can be rectified by changing the "#define SOURCE. . ." line in disloc.c to #define SOURCE "/disloc.c" and of course recompiling. --------------------------------------------------------------------- Name: disloc.ps disloc.ps Type: Macintosh BinHex Archive (application/mac-binhex40) Download Status: Not downloaded with message