The series show 21 days of 15-minute static solutions from processing L1-only GPS. Data graphed at +/-90 mm.
This graphs display contrasting noise levels on baselines of 4.1 km (SITE01) and 1.6 km (SITE02) length. The records show little if any displacement. Instead, the series show the general correlation between baseline length and scatter (RMS). Lower precision in the vertical is typical of GPS, due to the lack of low-elevation satellites. There may be additional bias at SITE01 due to a nearby high wall.
- Fifteen minute static solutions. Baseline length is 1.625 km. Displacement axis is +/-30 mm.
These graphs show two spans of data from the same baseline. The upper graph shows two days of data from early January, the second shows data from later that month (Jan 26-31). In the upper graph, there is no apparent displacement, and the scatter is minimal: 2, 1 and 3 mm RMS in the north, east and vertical (red, green and blue), respectively. In the lower graph, we see displacement to the west (green) and down (blue). The graphs reveal a level at which deformation can be resolved; in this case, clarified by residual offsets.
These ten-month series were generated from static-processing of 60-minute spans of L1-only GPS data. The three baselines range in length from 2.42 to 2.52 km. They are plotted over a range of +/-150 mm.
This graphic displays the records recorded by one of our MultiPoint field stations (MP-3), in which three GPS receivers are hosted within a single enclosure-power-radio system. The MP’s three antennae were deployed over a range of approximately 200 meters (-100, 0, +100 m). The series show:
A) The same general displacement trend across the deployment (northeast and down), but
B) A strengthening of the deformation signal as we move across the 200 meter station span (upper to lower graphs; 2-D map view).
The data are noisier from this network due to extreme limitations in satellite visibility, sometimes approaching 40 degrees for significant portions of the horizon.
Again, ten month series, static L1-only in 60-minute spans, plotted at +/-150 mm.
Very similar to the previous slide: these series are from a second MP-3 less than a half km away, and the timespan is the same. There is little displacement evident at these sites, though there may be some slight northeast motion in the upper two graphs. This shows the null case in comparison to the deformation occuring a short distance away.
- Over nine months of sixty-minute L1-static solutions, baseline lengths of ~2.15 km, displacement axis of +/-900 mm and time axis fixed across both graphs
Episodic slip, southwestward and down, recorded at two nearby (MultiPoint) sites over a ten month span. The record appears to begin during a slip episode which decelerates significantly after a few weeks. The lower graph shows the possible initiation of a second displacement episode beginning roughly one month after the end of the upper series. Two other series from this slope displayed similar features.
Four months of 15 minute L1-static solutions from baselines of 1.0 and 1.64 km. Trend lines from least-squares fit. Data graphed over a range of +/-900 mm, while two-D view is map view, N vs. E.
Secular displacement of two stations located on different sections of a slope. The interest here is in accelerations that could indicate imminent failure. The displacement vectors correlate well with the structure of the deforming slopes.