000005033 001__ 5033
000005033 005__ 20210215102112.0
000005033 0247_ $$2DOI$$a10.5194/se-12-363-2021
000005033 037__ $$aSCART-2020-0191
000005033 100__ $$avan Wijk, Kasper
000005033 245__ $$aSeismic monitoring of the Auckland Volcanic Field during New Zealand's COVID-19 lock-down
000005033 260__ $$c2021
000005033 500__ $$aThe city of Auckland, New Zealand (Tāmaki Makaurau, Aotearoa), sits on top of an active volcanic field. Seismic stations in and around the city monitor activity of the Auckland Volcanic Field (AVF) and provide data to image its subsurface. The seismic sensors – some positioned at the surface and others in boreholes – are generally noisier during the day than during nighttime. For most stations, weekdays are noisier than weekends, proving human activity contributes to recordings of seismic noise, even on seismographs as deep as 384 m below the surface and as far as 15 km from Auckland's Central Business District. Lockdown measures in New Zealand to battle the spread of COVID-19 allow us to separate sources of seismic energy and evaluate both the quality of the monitoring network and the level of local seismicity. A matched-filtering scheme based on template matching with known earthquakes improved the existing catalogue of five known local earthquakes to 35 for the period between 1 November 2019 and 15 June 2020. However, the Level-4 lockdown from 25 March to 27 April – with its drop in anthropogenic seismic noise above 1 Hz – did not mark an enhanced detection level. Nevertheless, it may be that wind and ocean swell mask the presence of weak local seismicity, particularly near surface-mounted seismographs in the Hauraki Gulf that show much higher levels of noise than the rest of the local network.
000005033 594__ $$aNO
000005033 6531_ $$aSeismic noise
000005033 6531_ $$aCOVID-19
000005033 6531_ $$aLockdown
000005033 700__ $$aChamberlain, Callum J
000005033 700__ $$aLecocq, Thomas
000005033 700__ $$aVan Noten, Koen
000005033 773__ $$c363–373$$pSolid Earth$$v12$$y2021
000005033 85642 $$ahttps://se.copernicus.org/preprints/se-2020-152/
000005033 8560_ $$fthomas.lecocq@observatoire.be
000005033 905__ $$apublished in
000005033 980__ $$aREFERD