Anthony Pivarunas

As a Research Geophysicist at the USGS California Observatory (CalVO), I work on volcanic history from the perspective of time (how long was a volcano active for?) and clusters (were these volcanoes active at the same time?). I also work with the Pacific Northwest Geologic Mapping Project to map out the Columbia River Basalt Group and other volcanic and sedimentary systems in Cascadia. I run the USGS Paleomagnetics Laboratory at Moffett Field, the latest incarnation of the laboratory where the Geomagnetic Polarity Time Scale was developed.

Research Examples:

Two short-lived shield volcanoes (Pivarunas et al., 2023)

How long does volcanism last at the large “regional” volcanos dotted around larger centers of Cascade volcanism like Shasta or Lassen? In northern California, the answer is: a few centuries at most. In this project, we used paleomagnetic data and numerical assessment of the change in the magnetic field (paleosecular variation) to delineate the lifetime of two 11 km3 shield volcanoes.

A far-traveled lava flow (Pivarunas et al., 2024)

How far away from a volcano might its lava end up? In the case of the vents at Tetherow Buttes, north of Bend, Oregon, the answer is: all the way to the Columbia River! In this project, we used multiple geological methods to correlate scattered outcrops of basalt which all belonged to the same lava flow. The presence of this lava across up to 180 km of Oregon provides a datum to assess river incision and history and tectonic deformation.