Fig. 15

Location of the BRMC gravity point. a Satellite image of the vicinity of BRMC derived from Google Earth Pro. The dashed line indicates the 60th parallel north, which corresponds to the border between the Yukon Territory (TY) and British Columbia (BC), Canada. When you access to BRMC (red circle), drive a van along the Haines Highway northward from Haines, and turn left after crossing over the Blanchard River. b Satellite image of BRMC derived from Google Earth Pro. The white line and yellow arrow indicate the access route to BRMC and the direction of the photo (c), respectively. BRMC (red circle) is located in the garage. c Garage of Blanchard Road Maintenance Compound. The white line indicates the access route to BRMC by car. The shutters at the tip of the white arrow can be opened when you transport AG instruments closely to the gravity point. d FG5-111 absolute gravimeter on the AG point. e Exact position of the AG point. It is located 129.3 cm from the corner of the gutter, and 220.5 cm from the corner of the red door. f Close-up photo of the AG point. This AG point was originally indicated with scratch marks of a small cross and a large square in and before 2012. However, the garage floor was painted by compound staff after the AG measurement in June 2012. Since we could not easily find the marks under the painting in June 2013, we highlighted the marks with a permanent marker for future AG measurements