Multiple factors went into selecting a site for each node, and the process of selecting sites began months before the fieldwork commenced. The goal was to create a grid of sites that were approximately 10 km apart spanning from Southwest Washington to the Oregon/California border in the coastal range. In addition, we wanted to create 6 east-west lines with node spacings ranging from 2 km to as little as 250 m in line with seismic profiles offshore. The initial placement of sites was refined based on accessibility and permitting in the months leading up to the deployment. The project leaders carefully examined maps, Google Earth satellite imagery and consulted with property owners to determine what regions were accessible either by car or a short hike from a road. Trips into the field to scout out sites helped determine road conditions and whether sites were gated and would require a key. In all, we had to keep track of more than a dozen different keys, with multiple copies of some of them.
Once in the field, small adjustments were made to the site placements based on a few factors. Most of these adjustments were made due to accessibility challenges that had not been identified using maps. Some teams encountered overgrown roads, small landslides or gates that were rusted shut. Another reason to relocate a site proximity to noise sources. Sites were located to avoid as much cultural noise (powerlines, homes, traffic, logging, etc.) and natural noise (rivers, trees, etc.) as possible. During the training, volunteers were taught the factors that went into choosing a site and learned how to relocate a site if they encountered a noisy or inaccessible site.
-Sarah Nolan