Geodetic GPS station P311 atop the Sierra Nevada mountains at Coyote Ridge, at an elevation of 3,699 meters, near Bishop, California. This station and many others show that these mountains are currently uplifting at 1–2 millimeters per year. (Image courtesy of Shawn Lawrence, UNAVCO.)

Exploring a Changing Continent Using a Plate Boundary Observatory


Geodesy is the science of measuring the size, shape, and gravity field of Earth, and how these change with time.
Transportable Array project staff in 2013.

Reflections on the Accomplishments of EarthScope’s USArray


The USArray has operated for over 15 years as a community science facility designed to address EarthScope’s goal of understanding the structure and evolution of the North American continent.
SAFOD scientists and core sample

San Andreas Fault Observatory at Depth


The Gold Standard for Scientific Drilling Through an Active, Continental Transform Fault


top 10

EarthScope Top 10 Discoveries


stomp test

Alaska Amphibious Experiment Crosses the Shoreline


New ocean-bottom seismometers complement the Transportable Array
Station RLAP

PBO Station Highlight: A Puzzle in the Midcontinent


What causes earthquakes in the interior of North America, far from plate boundaries?
The El Mayor-Cucapah earthquake rupture across a road

PBO Station Highlight: P496 Is Only One Piece of the Story


PBO station P496 not only shook during the 7.2 El Mayor–Cucapah earthquake in northwestern Mexico, but moved permanently as a result of it.


P472: Engineering for Earthquakes

P472: Engineering for Earthquakes


PBO Station Highlight October 2017
Elliot Wilson of Pioneer Earthworks operates the drill at Alaska Transportable Array station D27M. (Photo by Max Enders, IRIS).

EarthScope's Transportable Array Spans Alaska, the Last Frontier


Elliot Wilson of Pioneer Earthworks operates the drill at Alaska Transportable Array station D27M. Photo by Max Enders, IRIS.

PBO Station P085

P085: Tiny Motions Matter


PBO Station Highlight Summer 2017
Barry White installing an infrasound sensor

Transportable Array Equips Stations with Infrasound Sensors


by Andy Frassetto and Kasey Aderhold, IRIS - NSF # SAGE: 1261681, MRI-R2: 0960275 | Summer 2017

Observations of infrasonic signals have…

PBO Site

AB50: Quick Responder


PBO Station Highlight May 2017
Seismology in the Classroom

Seismology in the Classroom


A new online course connects teachers across Alaska to real-time seismic data
P208 in California. Credit UNAVCO

Salt Canyon, California


PBO Station P208 watches the grass grow...literally
The Alaska Transportable Array deployment coordinator, field operations managers, and station specialists. Photo credit: Maria Sanders, Jeremy Miner, and Ryan Bierma

The Alaska Transportable Array Team


Achieving Success in Challenging Environments


The Dempster Highway winds southward in the distance from station TA.G30M, situated north of the Arctic Circle.

Driving the Dempster


The Transportable Array deploys along a remote Canadian “highway”
IRIS 2016 workshop participants gathered in Vancouver, WA, for a week of scientific presentations, discussions, field trips, and workshops.

IRIS 2016 Workshop


Highlights Emerging Fields and Technologies in Seismology
PBO Station AV03

Augustine Island, Alaska


PBO Station AV03 Takes a Blow
UNAVCO banner

2016 UNAVCO Science Workshop


New Uses for the Plate Boundary Observatory


Installed seismometer and continuous GPS site. Canada

Supporting Earth Science in the Canadian Sub-Arct


By Justin Sweet - Winter 2016

Canada’s Yukon and Northwest Territories are not known as hospitable land. This sub-arctic region, home to the Mackenzie Mountains project, presented

Station AC46

Back to Mothership


How PBO data get from Everywhere to somewhere
The accelerometer installed at P248, clamped to the vertical leg of the GPS monument. (Photo Doerte Mann, UNAVCO)

Low-Cost Additions to the Plate Boundary Observatory for Earthquake Early Warning


By Doerte Mann and Beth Bartel - Spring 2015

One of the major benefits of the Plate Boundary Observatory (PBO) is its contribution to prototype Earthquake Early Warning systems (EEW).

Location of broadband seismic stations operating in the continental US before EarthScope (white circles). The Transportable Array leaves behind 260 new “legacy” stations (all non-white circles).

The Legacy of the USArray Transportable Array


By Andy Frassetto, IRIS - Spring 2015

In the fall of 2003, before EarthScope began, approximately 200 modern broadband seismic stations operated across the contiguous United States,


Magnetotelluric Transportable Array and Backbone Location

USArray Continues Field Activities in 2014


By Perle Dorr, IRIS - Summer 2014

Since the completion of the Transportable Array in the Lower 48 during fall 2013, USArray has focused on the creation of the Central and Eastern US

Earthscope Globe

Transportable Array Contributes to the Central and Eastern US Network


By Perle Dorr, IRIS - Spring 2014

The National Science Foundation is funding the creation of a Central and Eastern US Network (CEUSN) for the purpose of obtaining long-…

Earthscope Globe

Stability of PBO GPS Monument Types


Project Highlight
Dark, ash-covered snow near the summit of Shishaldin Volcano in the Aleutians is evidence of ongoing low-level eruptive activity near PBO’s AV37 GPS station. (Photo/Ryan Bierma, UNAVCO)

Helicopter Fieldwork in the PBO Alaska Region


By Ellie Boyce - Summer 2014

With high-elevation GPS stations melting out of the snow and the weather becoming milder, the PBO Alaska region began annual helicopter-based…


Earthscope Globe

USArray Reaches the East Coast


By Maureen Long and Vadim Levin - Winter 2014

On October 1st 2013 the seismic and magnetotelluric observatory network USArray, which is a key element of the EarthScope…

Earthscope Globe

USArray Looks Back as it Looks Ahead


By IRIS - Fall 2013

Ten years ago, the construction of USArray observatories officially began. This followed numerous community meetings, countless hours of meticulous…

Earthscope Globe

USArray - Alaska Deployment Planning


Terry Pavlis, UTEP - Spring 2013

On February 19 and 20 approximately 50 geoscientists met at the Pacific Geoscience Center in Sydney, British Columbia, to discuss…

Earthscope Globe

USArray Infrasound Data Products at IRIS


By Manochehr Bahavar and Chad Trabant - Summer 2013

Diverse natural and man-made acoustic sources such as large explosions, rocket launches, and meteorites can act as…

Earthscope Globe

USArray Status


By Perle Dorr, IRIS

With operating stations blanketing the southeastern states, the Transportable Array is on target to complete its journey across the contiguous US and…


Earthscope Globe

PBO GPS Updates


By Glen Mattioli, UNAVCO - Fall 2012

Currently, there are 1120 GPS sites and 28 tilt meters, as well as numerous other strainmeters actively measuring deformation. In…

Earthscope Globe

Tales from the Field: PBO Installation in Alaska


Max Enders - Spring 2012

When UNAVCO set about building the Earthscope Plate Boundary Observatory (PBO) no challenge was nearly as daunting as the prospect of installing…

Earthscope Globe

Spring 2012 Facilities Status


Spring 2012

USArray Status

The Transportable Array (TA) continues to roll eastward across the US. Having crossed the Mississippi River in March 2011, the TA will…