loading page

Nyiragongo crater collapses measured by multi-sensor SAR amplitude time series
  • +6
  • Delphine Smittarello,
  • Raphael Grandin,
  • Maxime Jaspard,
  • Dominique Derauw,
  • Nicolas F. d'Oreye,
  • Tara Shreve,
  • Marina Debret,
  • Nicolas Theys,
  • Hugues Henri Brenot
Delphine Smittarello
European Center for Geodynamics and Seismology

Corresponding Author:[email protected]

Author Profile
Raphael Grandin
Université de Paris, Institut de physique du globe de Paris, CNRS
Author Profile
Maxime Jaspard
European Center for Geodynamics and Seismology
Author Profile
Dominique Derauw
Centre Spatial de Liège and Universidad Nacional de Rio Negro
Author Profile
Nicolas F. d'Oreye
National Museum of Natural History of Luxembourg and European Center for Geodynamics and Seismology
Author Profile
Tara Shreve
Carnegie Institution for Science
Author Profile
Marina Debret
École & observatoire des sciences de la Terre - EOST
Author Profile
Nicolas Theys
Royal Belgian Institute for Space Aeronomy (BIRA-IASB)
Author Profile
Hugues Henri Brenot
Author Profile


Crater morphology at active volcanoes can change rapidly. Quantifying changes during the course of a volcanic unrest episode may help assess the level of volcanic activity. However, limitations such as crater accessibility, cloud cover or intra-crater eruptive activity may hamper regular optical or on-site crater monitoring. Here we use multi-sensor satellite Synthetic Aperture Radar (SAR) imagery to produce dense time series of quantitative indicators of crater morphological changes. High temporal resolution is achieved by combining images from a variety of sensors and acquisition modes, though the diversity of acquisition geometries (incidence angle, viewing direction, resolution…) prevents direct comparison between the different images. Using basic trigonometry assumptions, we develop PickCraterSAR, an open-access tool written in Python to measure crater radius and depth from SAR amplitude images in radar geometry. We apply our methodology to study the crater collapse associated with the May 2021 and January 2002 eruptions of Nyiragongo volcano. After the 2021 collapse, we estimate the maximum depth of the crater to be 850 m below the rim and the total volume to be 84$\pm$10 Mm$^3$ (270 m deeper but only 15-20 \% more voluminous than the post-2002 eruption crater). We also show that the 2021 crater collapse occurred progressively while a dike intrusion was migrating toward the south.
22 Mar 2023Submitted to ESS Open Archive
26 Mar 2023Published in ESS Open Archive