SN11

3/27/00

00 47.27 S LATITUDE
91 08.29 W LONGITUDE

General Location and Strategy: SN11 is on the northern caldera rim. It is part of the rim grid. Also, it is inboard of the vents of several of the most recent eruptive vents, so it should be well placed to catch a diking event.
 

Field Notes:

Days measured:  03 Jan 00 - 06 Jan 00

(N rim of caldera)

Monument SN11 is located on top of a narrow spatter ridge surrounded by slabby pahoehoe.  The spatter ridge is oriented with its long axis N-S, and sits 6m high by 30m long above the surroundings; it looks like a small cone from the east.  North of site SN11 is the moat between the caldera "rim" and the circumferential fissures; the "moat" itself is quite flat with ponded pahoehoe.  South of the site are several benches and faults stepping down into the caldera.  The overall slope at the site is southward into the caldera, thus lava from the surrounding circumferential vents has flowed southward into the caldera in this area.

Antenna height:  0.549m + 0.108m = 0.657m
Antenna offset:  0.353m

Power up:  1500h (local), 03 Jan 00; [restart SN11-B @ 1220h (local), 05 Jan 00]
Power down:  1600h (local), 04 Jan 00; [SN11-B @ 1756h (local), 06 Jan 00]
 

2000 Results

Data from 3 days was processed and combined for the following solution, 1/4-1/6/00.  Solution was made by fixing Base (SN01), although SN01 was down for much of the day on 1/4/00.

Owing to the shutdown of SN01 on 1/4/00, SN11 was used as a reference site on that day, using the coordinates reported here.

The first reported uncertainty uses the sigma of the coordinate group as a scaling factor and may be too pessimistic. The second uses the sigma of the single difference observations as a scaling factor.

X = -126716.5051 ± 2.6, 0.4 mm
Y = -6377378.805 ± 28.1, 2.9 mm
Z = -87139.5372 ± 5.1, 0.4 mm

Ht. 1099.7850
Lat. -0 47 16.623373
Long. - 91 08 17.877404

View across NE corner of caldera to SN11 and SN21. From SN12.

View from about 200 m NE.