Airborne geophysical surveys

Survey name	Type	Altitude	Spacing	Flight line distance
Hoquiam	M/R-D	121.9 m	9.60 km	2,282 km
Centralia	M-D	200 m above ground	0.40 km	23,501 km
Puget Sound 1997	M-D	244 m above ground	0.40 km	69,202 km
Seattle	M/R-D	121.9 m	9.60 km	1,866 km
Southwest Washington '51	M-Dz	304.8 m above ground	0.80 km	4,090 km
Morton	M-D	304.8 m above ground	0.80 km	2,698 km
Puget Sound	M-D	914.4 m (barometer)	1.60 km	4,908 km
Olympic Pen.-South	M-Dz	762 m (barometer)	3.20 km	2,471 km
East Puget Sound	M-D	914.4 m (barometer)	3.20 km	3,001 km
Puget Lowlands A	M-D	243.8 m above ground	0.40 km	63,464 km