Eruption frequency and magnitude in a geothermally active continental rift: The Bora-Baricha-Tulla Moye volcanic complex, Main Ethiopian Rift

Research output: Contribution to journalArticleResearchpeer-review

Authors

  • Amdemichael Zafu Tadesse
  • Karen Fontijn
  • Abate A. Melaku
  • Gebru
  • Victoria Smith
  • Emma L. Tomlinson
  • Dan N. Barford
  • Florence Bégué
  • Luca Caricchi
  • Priya Laha
  • Herman A. Terryn
  • Snorri Gudbrandsson
  • Gezahegn Yirgu
  • Dereje Ayalew

External Organisational units

  • Département de Physique, Université libre de Bruxelles, Campus de la Plaine, 1050 Bruxelles, Belgium
  • University of Oxford
  • Addis Ababa University
  • Université Fribourg
  • Trinity College Dublin
  • Scottish Universities Environmental Research Center
  • University of Geneva
  • Vrije Universiteit Brussel
  • Reykjavik Geothermal Ltd.

Abstract

Based on the review of a wide range of literature, this paper finds that: (1) the average specific surface energy of various single crystals is only 0.8 J/m2. (2) The average specific fracture energy of the rocks with a pre-crack under static cleavage tests is 4.6 J/m2. (3) The average specific fracture energy of the rocks with a pre-cut notch but with no pre-crack under static tensile fracture (mode I) tests is 4.6 J/m2. (4) The average specific fracture energies of regular rock specimens with neither pre-made crack nor pre-cut notch are 26.6, 13.9 and 25.7 J/m2 under uniaxial compression, tension and shear tests, respectively. (5) The average specific fracture energy of irregular single quartz particles under uniaxial compression is 13.8 J/m2. (6) The average specific fracture energy of particle beds under drop weight tests is 74.0 J/m2. (7) The average specific fracture energy of multi-particles in milling tests is 72.5 J/m2. (8) The average specific energy of rocks in percussive drilling is 399 J/m3, that in full-scale cutting is 131 J/m3, and that in rotary drilling is 157 J/m3. (9) The average energy efficiency of milling is only 1.10%. (10) The accurate measurements of specific fracture energy in blasting are too few to draw reliable conclusions. In the last part of the paper, the effects of inter-granular displacement, loading rate, confining pressure, surface area measurement, premade crack, attrition and thermal energy on the specific fracture energy of rock are discussed.

Details

Original languageEnglish
Pages (from-to)629-667
Number of pages39
JournalJournal of volcanology and geothermal research
Volume423.2022
Issue numberMarch
DOIs
Publication statusPublished - 15 Jan 2022