Abstract
Constraining upward mantle flow is crucial to understand global mantle flow and directly link the Earth’s interior with the surface. However, mantle upwellings that connect the deep mantle to the surface are poorly understood. The goal of the UPFLOW project (https://upflow-eu.github.io) is to develop new high-resolution seismic imaging methods along with new data collection to greatly advance our understanding of upward mantle flow. UPFLOW deployed 50 and recovered 49 ocean bottom seismometers (OBSs) in a ~1,000×2,000 km2 area in the Azores-Madeira-Canaries region starting in July 2021 for ~13 months, with an average station spacing of ~150-200 km. The experiment included institutions from five different countries: Portugal (IPMA, IDL, Univ. of Lisbon, ISEL), Ireland (DIAS), UK (UCL), Spain (ROA) and Germany (Potsdam University, GFZ, GEOMAR, AWI). Most of the instruments had three-component wideband seismic sensors and hydrophones, but three different designs of OBS frames were used. Our analysis shows high-quality data, notably a substantial noise decrease in vertical component long-period data (T>~30s). We show illustrative recordings of teleseismic, local events and non-seismic signals (whales, ships, Tonga eruption), as well as systematic analyses of the background noise levels, clock skew and horizontal component rotation angles.UPFLOW team: Ana MG Ferreira, Miguel Miranda, Sameneh Baranbooei, Roberto Cabieces Diaz, Mafalda Carapuço, Carlos Corela, José Luis Duarte, Henrique Ferreira, Wolfram H. Geissler, Katrina Harris, Stephen Hicks, Kasra Hosseini, Frank Krueger, Dietrich Lange, Afonso Loureiro, Peter Makus, Augustin Marignier, Marta Neres, Luis Ramos, Theresa Rhein, Alex Saoulis, David Schlaphorst, Frederik Tilmann, Maria Tsekhmistrenko, Kuan-Yu Ke.
