The Alpine fault runs parallel to, and just inland of, much of the west
coast of New Zealand's South Island. This view was created from the
near-global digital elevation model produced by the Shuttle Radar
Topography Mission (SRTM) and is almost 500 kilometers (just over 300
miles) wide. Northwest is toward the top. The fault is extremely distinct
in the topographic pattern, nearly slicing this scene in half lengthwise.
In a regional context, the Alpine fault is part of a system of faults
that connects a west dipping subduction zone to the northeast with an
east dipping subduction zone to the southwest, both of which occur along
the juncture of the Indo-Australian and Pacific tectonic plates. Thus,
the fault itself constitutes the major surface manifestation of the plate
boundary here. Offsets of streams and ridges evident in the field, and in
this view of SRTM data, indicate right-lateral fault motion. But
convergence also occurs across the fault, and this causes the continued
uplift of the Southern Alps, New Zealand's largest mountain range, along
the southeast side of the fault.
Two visualization methods were combined to produce this image: shading
and color coding of topographic height. The shade image was derived by
computing topographic slope in the northwest-southeast (image top to
bottom) direction, so that northwest slopes appear bright and southeast
slopes appear dark. Color coding is directly related to topographic
height, with green at the lower elevations, rising through yellow and
tan, to white at the highest elevations.
Elevation data used in this image were acquired by the Shuttle Radar
Topography Mission aboard the Space Shuttle Endeavour, launched on Feb.
11, 2000. SRTM used the same radar instrument that comprised the
Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR)
that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed
to collect 3-D measurements of the Earth's surface. To collect the 3-D
data, engineers added a 60-meter (approximately 200-foot) mast, installed
additional C-band and X-band antennas, and improved tracking and
navigation devices. The mission is a cooperative project between NASA,
the National Geospatial-Intelligence Agency (NGA) of the U.S. Department
of Defense and the German and Italian space agencies. It is managed by
NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth
Science Enterprise, Washington, D.C.
Size: 495 kilometers (307 miles) by 162 kilometers (100 miles)
Location: 43.2 degrees South latitude, 170.5 degrees East longitude
Orientation: Northwest toward the top
Image Data: Shaded and colored SRTM elevation model
Date Acquired: February 2000
