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The UPFLOW Experiment: Peeking from the Sea Floor to the Deep Mantle with an ~1,500 KM Aperture Array of 49 Ocean Bottom Seismometers in the Mid-Atlantic

Description: 

Constraining upward mantle flow is crucial to understand global mantle flow and directly link the Earth’s interior with the surface. However, plume-like mantle upwellings that connect the deepest 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, and to use them to greatly advance our understanding of upward mantle flow. We carried out a large amphibian experiment in the Azores-Madeira-Canaries region, which is a unique natural laboratory with multiple mantle upwellings that are poorly understood. UPFLOW deployed 50 and recovered 49 ocean bottom seismometers (OBSs) in a ~1,000×2,000 km2 area in the study region starting in July 2021 for ~13 months, with an average station spacing of ~150-200 km. These data will be combined with observations from over 30 seismic land stations in nearby islands. 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). 32 OBSs were loaned from the DEPAS international pool of instruments maintained by the Alfred Wegener Institute (Bremerhaven), Germany, while other institutions borrowed additional instruments (7 from DIAS, 4 from IDL, 3 from ROA, 4 from GEOMAR). Most of the instruments have three-component wideband seismic sensors and hydrophones, but three different designs of OBS frames were used. Initial data analysis shows high-quality data, notably a substantial decrease in noise levels in the vertical component long-period data (T>~30s). We show illustrative recordings of teleseismic events, a local seismic swarm, and long-period seismic signals as well as of non-seismic signals such as whales vocalisations and ships’ noise. We analyse the data performance as a function of the three models of OBS, recorder and seismometer types.

Session: Earth’s Structure From the Crust to the Core

Type: Oral

Date: 4/18/2023

Presentation Time: 11:00 AM (local time)

Presenting Author: Roberto Cabieces

Student Presenter: No

Invited Presentation: 

Authors