Due to local, state, federal, and international travel restrictions in response to the COVID-19 pandemic and with the support of the National Science Foundation (NSF), IRIS postponed the planned removal of the Alaska Transportable Array (TA) network until the 2021 field season. Data telemetry will continue to be supported until May 2021 and the Array Network Facility (ANF) will continue to support archival at the IRIS Data Management Center (DMC) along with processing onsite baler media as it is returned from removals.
Several Alaska TA stations were removed during the 2020 field season to simplify logistics for the bulk of the removals in the 2021 season. All field personnel strictly followed all regulations and restrictions, as well as a project-specific health and safety plan. Baler media has been returned from this set of removed stations, which ANF uses to patch any gaps in the telemetered data, and metadata has been closed out.
A proposal submitted by the Alaska Earthquake Center (AEC) in response to the 19-048 NSF Dear Colleague Letter “Repurposing the Alaska Transportable Array to Support Observations of Arctic Environmental Change” was funded, which included the adoption and continued operation of 45 additional Alaska TA stations. These stations were transferred to the AEC in September and data will continue to be archived under the AK network code. This change of network code and, in some cases, a change in sample rate or channel/location code, may require adjusting data retrieval scripts. The full list of adopted or continuing Transportable Array stations is available under the virtual network _US-TA-ADOPTED
A paper on the Alaska Transportable Array will be published in a focus section of Seismological Research Letters and is already available online at: https://doi.org/10.1785/0220200154. A longer format final report is in preparation and will be made available at: http://www.usarray.org/alaska.
IRIS would like to thank the National Science Foundation for their continued support of the Alaska Transportable Array project through NSF Award EAR-1261681.
— Bob Busby and the Transportable Array Team