TY - JOUR

T1 - Eruption frequency and magnitude in a geothermally active continental rift

T2 - The Bora-Baricha-Tulla Moye volcanic complex, Main Ethiopian Rift

AU - Tadesse, Amdemichael Zafu

AU - Fontijn, Karen

AU - Melaku, Abate A.

AU - Gebru, null

AU - Smith, Victoria

AU - Tomlinson, Emma L.

AU - Barford, Dan N.

AU - Gopon, Phillip

AU - Bégué, Florence

AU - Caricchi, Luca

AU - Laha, Priya

AU - Terryn, Herman A.

AU - Gudbrandsson, Snorri

AU - Yirgu, Gezahegn

AU - Ayalew, Dereje

PY - 2022/1/15

Y1 - 2022/1/15

N2 - 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.

AB - 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.

U2 - 10.1016/j.jvolgeores.2022.107471

DO - 10.1016/j.jvolgeores.2022.107471

M3 - Article

VL - 423.2022

SP - 629

EP - 667

JO - Journal of volcanology and geothermal research

JF - Journal of volcanology and geothermal research

SN - 0377-0273

IS - March

ER -