USGS: “In this photo, a survey tripod is established over a benchmark near the summit of Mauna Loa; Moku‘āweoweo caldera is visible in the background on the image.” (USGS image by A. Ellis)

(BIVN) – Recent photos published on the USGS Hawaiian Volcano Observatory website show the annual GPS survey of Mauna Loa is underway.

Mauna Loa is not erupting and the alert level for the giant Hawaiʻi island volcano at GREEN / NORMAL.

The USGS describes the GPS survey in this May 23 caption:

During the annual Mauna Loa GPS campaign, scientists temporarily deploy a number of GPS instruments at established benchmarks; their recorded positions can be compared with those from previous years to discern subtle patterns of ground deformation associated with volcanic activity. These data augment the permanent, continuously recording GPS instruments in HVO’s monitoring network.

The USGS says “most Mauna Loa GPS campaign survey sites have been occupied every year since 1996, whereas less active volcanoes Hualālai and Haleakalā are surveyed every 3–5 years.”

According to the most recent HVO update on Mauna Loa published on May 4, 2023, no significant activity was detected at Mauna Loa volcano during the past month.

“The number of detected earthquakes remained at background levels and most events were smaller than M2.0,” the scientists wrote. “Data from Global Positioning System (GPS) instruments on Mauna Loa indicate slow inflation as magma replenishes the summit reservoir system.”

Also, “gas and temperature data from a station on the Southwest Rift Zone showed no significant changes over the past month”, the USGS report stated.