Articles | Volume 12, issue 1
https://doi.org/10.5194/se-12-187-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/se-12-187-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
27 Jan 2021
Research article |
| 27 Jan 2021
| 27 Jan 2021
A systems-based approach to parameterise seismic hazard in regions with little historical or instrumental seismicity: active fault and seismogenic source databases for southern Malawi
Jack N. Williams
CORRESPONDING AUTHOR
School of Earth and Environmental Sciences, Cardiff University, Cardiff, UK
Hassan Mdala
Geological Survey Department, Mzuzu Regional Office, Mzuzu, Malawi
Åke Fagereng
School of Earth and Environmental Sciences, Cardiff University, Cardiff, UK
Luke N. J. Wedmore
School of Earth Sciences, University of Bristol, Bristol, UK
Juliet Biggs
School of Earth Sciences, University of Bristol, Bristol, UK
Zuze Dulanya
Geography and Earth Sciences Department, University of Malawi, Zomba, Malawi
Patrick Chindandali
Geological Survey Department, Zomba, Malawi
Felix Mphepo
Geological Survey Department, Mzuzu Regional Office, Mzuzu, Malawi
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Mapping and compiling the attributes of faults capable of hosting earthquakes are important for the next generation of seismic hazard assessment. We document 18 active faults in the Luangwa Rift, Zambia, in an active fault database. These faults are between 9 and 207 km long offset Quaternary sediments, have scarps up to ~30 m high, and are capable of hosting earthquakes from Mw 5.8 to 8.1. We associate the Molaza Fault with surface ruptures from two unattributed M 6+ 20th century earthquakes.
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C. Scott Watson, John R. Elliott, Susanna K. Ebmeier, Juliet Biggs, Fabien Albino, Sarah K. Brown, Helen Burns, Andrew Hooper, Milan Lazecky, Yasser Maghsoudi, Richard Rigby, and Tim J. Wright
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Mapping and compiling the attributes of faults capable of hosting earthquakes are important for the next generation of seismic hazard assessment. We document 18 active faults in the Luangwa Rift, Zambia, in an active fault database. These faults are between 9 and 207 km long offset Quaternary sediments, have scarps up to ~30 m high, and are capable of hosting earthquakes from Mw 5.8 to 8.1. We associate the Molaza Fault with surface ruptures from two unattributed M 6+ 20th century earthquakes.
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We present new data on the orientation of fractures, their fill, and their density around the Alpine Fault, a plate boundary fault on the South Island of New Zealand. Fractures < 160 m of the fault are filled and show a range of orientations, whilst fractures at greater distances (< 500 m) are open and parallel to the rock's mechanical weakness. We interpret the latter fracture set to reflect near-surface processes, whilst the latter are potentially linked to deep-seated Alpine Fault seismicity.
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Subject area: Tectonic plate interactions, magma genesis, and lithosphere deformation at all scales | Editorial team: Rock deformation, geomorphology, morphotectonics, and paleoseismology | Discipline: Tectonics
First evidence of active transpressive surface faulting at the front of the eastern Southern Alps, northeastern Italy: insight on the 1511 earthquake seismotectonics
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We first investigated the recent activity of a major active fault system, probably responsible for the 1511 earthquake, one of the most destructive seismic events of the eastern Alps and of continental Europe over the past millennium.
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Short summary
Earthquake hazard is often specified using instrumental records. However, this record may not accurately forecast the location and magnitude of future earthquakes as it is short (100s of years) relative to their frequency along geologic faults (1000s of years). Here, we describe an approach to assess this hazard using fault maps and GPS data. By applying this to southern Malawi, we find that its faults may host rare (1 in 10 000 years) M 7 earthquakes that pose a risk to its growing population.
Earthquake hazard is often specified using instrumental records. However, this record may not...
