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First CocoNET Continuously Operating GPS Station Installed

  • UNAVCO Engineer: Sarah Doelger
  • Dates: June 2011
  • Location: Cocos Islands, Caribbean
  • Funding Source: The National Science Foundation

Written by Sarah Doelger



COCONet seeks to understand the factors that control earthquake and hurricane hazards by adding 50 high-precision permanent GPS stations to 50 existing ones. These instruments are able to detect millimeter changes in the movement of Earth's crust and atmospheric water vapor that helps predict the path of hurricanes.

Ultimately, COCONet data will provide important information about meteorology, earthquakes, and volcanic activity. Although scientists often use UNAVCO's GPS systems to measure tectonic movements in earthquake zones, they can also use the GPS radio frequency signals to estimate how much moisture is available in the atmosphere.

The first CocoNET continuously operating GPS station was installed in late May 2011 on Cocos Island in the Pacific Ocean, 340 miles off the coast of Costa Rica. The island is located in the middle of the Cocos plate, which subducts below the Carribean plate to the east.

For more information, please see the COCONet Highlight


Over eighty million people live in Central America and in the Caribbean Islands, with many people living in the zones of maximum earthquake activity. The warm water and air temperatures of the Carribbean region also produce hurricanes and related heavy rains and landslides which create tremendous problems.

Understanding the factors that control these hazards requires getting more real-time data along earthquake zones and data from the atmosphere over the Caribbean Ocean. COCONet will help to do this.

Geology and Terrain

The geology of the island is primarily basaltic, the landscape very mountainous, and the foliage dense and lush. Cocos is approximately 24 square kilometers in area, but limited appropriate or accessible spots for a GPS station exist. The island is a national park of Costa Rica and remains uninhabited save for a Ranger outpost in one of its few protected bays. The GPS equipment was ultimately installed in an open field, cleared by the park service, which serves as an emergency helicopter landing for the ranger outpost.

Station Construction

The station was constructed by Scientists Dr. Marino Protti and Victor Gonzalez (of the Universidad Nacional de Costa Rica) and Unavco Field Engineer Sarah Doelger. The team remained on the island for a week due to restricted boat access. Voyage by boat is the primary means of transportation to the island. The journey takes 36 hours from the Costa Rican western shore. The monument is identical to the PBO Short-Drilled-Braced model, and is grouted into well consolidated soils. A hand auger was used to create the holes for each monument leg. The station is online via a wireless radio connection to the main ranger building which has a VSAT internet link. The station is powered by a nearby AC drop.


Last modified: 2020-02-03  20:49:04  America/Denver