Media Alert: Flights Above Puerto Rico to Map Geology

USGS Low-level Airplane Surveys Beginning February

By Bipartisan Infrastructure Law Investments February 23, 2023

Editor: In the public interest and in accordance with Federal Aviation Administration regulations, the USGS is announcing this low-level airborne project. Your assistance in informing the local communities is appreciated.

RESTON, Va. A low-flying airplane will soon be visible to residents of Puerto Rico beginning in February and lasting potentially through May 2023.

The low-level flights are being coordinated by the U.S. Geological Survey (USGS). Their goal is to image geology at the surface and below ground using airborne geophysical technology. This effort represents a collaboration between the USGS Earth Mapping Resources Initiative (Earth MRI), Earthquake Hazards Program and Coastal and Marine Hazards and Resources Program.

Image shows a map of Puerto Rico with earthquakes marked with colored circles and a black box where the surveys will happen — The flights will cover the entire island, as well as surrounding waters. The survey area is marked on the map with a black polygon. The colored circles mark the locations of earthquakes that have occurred since 1986 at various depths, denoted by the color of the circle.

The USGS Earthquake Hazards Program is working to better understand faults, seismicity and the related geologic hazards throughout the US. The USGS Coastal and Marine Hazards and Resources Program studies coastal and ocean resources and processes from shorelines and estuaries to the continental shelf and deep sea. Earth MRI is a nationwide collaboration between the USGS and state geologists to modernize our understanding of the nation’s fundamental geologic framework through new geologic maps, geophysical and topographic surveys, and geochemical sampling. Recent funding by the Bipartisan Infrastructure Law has facilitated coverage of such a large area.

This state-of-the-art, high-resolution survey is the first of its kind for Puerto Rico. The only public airborne geophysical surveys over Puerto Rico were small, low-resolution surveys flown in 1957 and 1962, before GPS and other modern equipment were available.

Image shows a small aircraft at an airport with a stinger tail on it for the airborne geophysical data collection — **A typical survey airplane. The magnetic sensor is placed in an extension on the back of the airplane to reduce the impact of the airplane’s own magnetic field.**

Instruments on the airplane will measure variations in the Earth’s magnetic field and natural low-level radiation created by different rock types up to several miles beneath the surface. This information will help researchers develop geologic maps in three dimensions, which in turn will provide scientists with the framework needed to better evaluate earthquake hazards, natural resources, landslides, etc. The scientific instruments on the airplane are completely passive with no emissions that pose a risk to humans, animals, or plant life. No photography or video data will be collected. The data collected will be made freely available to the public once complete.

This survey will be flown at a height of 300 to 1,000 feet above ground by contractor Terraquest Ltd. Experienced pilots who are specially trained and approved for low-level flying will operate the aircraft. All flights will occur during daylight hours and are coordinated with the Federal Aviation Administration to ensure accordance with U.S. law.