Table 1 List of the grid searches. East and north are measured from the summit. Elevation is above sea level. The residual E is based on Eq. (2) for the best-fit solution of each search. The first search was conducted for all four source mechanisms, and the best-fit tensile crack solution is shown. The second and third searches were conducted only for a tensile crack
From: Source mechanism of a VLP event immediately before the 2014 eruption of Mt. Ontake, Japan
Parameter | Minimum | Maximum | Interval | Best-fit solution |
|---|---|---|---|---|
First search | ||||
East | −3200 m | 3200 m | 200 m | −400 m |
North | −3200 m | 3200 m | 200 m | −400 m |
Elevation | −3200 m | 2800 m | 200 m | 2000 m |
θ | 0° | 90° | 15° | 75° |
φ | 0° | 345° | 15° | 0° |
E | 56.1 % | |||
Second search | ||||
East | −1400 m | 600 m | 40 m | −320 m |
North | −1400 m | 600 m | 40 m | −440 m |
Elevation | 1000 m | 2800 m | 40 m | 2040 m |
θ | 30° | 120° | 5° | 80° |
φ | −45° | 45° | 5° | 5° |
E | 55.2 % | |||
Third (final) search | ||||
East | −720 m | 80 m | 40 m | −360 m |
North | −840 m | −40 m | 40 m | −480 m |
Elevation | 1640 m | 2440 m | 40 m | 2040 m |
θ | 65° | 95° | 1° | 79° |
φ | −10° | 20° | 1° | 6° |
E | 55.1 % | |||