Probabilistic Seismic Hazard Assessment for the Democratic Republic of Congo and Surrounding Areas

Abstract

A probabilistic approach was used to map the seismic hazard in Democratic Republic of Congo and surrounding areas, and assess the seismic hazard level for 14 cities in the region. Seismic hazard maps for 2%, 5% and 10% chance of exceeding the indicated ground accelerations in 50 years were prepared using a homogenised 90-year catalogue compiled for moment magnitudes; the attenuation relations of Mavonga (for the Western Rift Valley of Africa), Jonathan (for eastern and southern Africa) and Atkinson and Boore (for eastern North America); and the EZ-Frisk software package. The highest levels of seismic hazard were found in the Lake Tanganyika Rift seismic zone, where peak ground accelerations in excess of 0.32 g, 0.22 g and 0.16 g are expected to occur with 2%, 5% and 10% chance of exceedence in 50 years, respectively. The seismic hazard in the Congo Basin diminishes with distance away from the Western Rift Valley until, at a distance of about 450 km, the chance of exceeding 0.05 g (the threshold value of engineering interest) is less than 10% in 50 years.

Studies of crustal structure, seismic precursors to volcanic eruptions and earthquake hazard in the eastern provinces of the Democratic Republic of Congo

“…A probabilistic approach (Cornell, 1968;McGuire, 1976 andMcGuire, 1993) was used to map the seismic hazard in DRC and surrounding areas (Mavonga and Durrheim, 2009). Probabilistic seismic hazard analysis involves three main steps: definition of seismic source zones, determination of seismicity parameters for each source zone, and preparation of seismic hazard maps.…”

“…All available instrumental seismic data covering the region 14°S to 6°N and 10°E to 32°E for the period 1910-2008 were compiled in a catalogue homogenized according to the moment magnitude scale M w (Mavonga and Durrheim, 2009). All of the DRC, with the exception of the westernmost region, was included in the study area, together with parts of Uganda, Tanzania, Rwanda, Burundi, Sudan and Zambia.…”

Source parameters of the 2008 Bukavu-Cyangugu earthquake estimated from InSAR and teleseismic data

“…For example the low‐magnitude tectonic earthquakes recorded in the VVP (generally ≤ M w 4) contrast with stronger events recorded elsewhere in the Kivu basin (≤ M w 6.2) and with major events recorded in the adjacent Albertine and Tanganyika basins (≤ M w 7). In the less mature western branch, aside from volcanic provinces, most of the extension is accommodated through slip along the basins’ border faults (Albaric et al 2009; Mavonga & Durrheim 2009; Delvaux & Barth 2010).…”

“…Earthquakes larger than magnitude 5 are uncommon in the Kivu basin (Barth et al 2007; Mavonga 2007; Mavonga & Durrheim 2009; Delvaux & Barth 2010). According to the USGS catalogue (1973 to present), the Bukavu earthquake is the second largest earthquake recorded in this area, following the M w 6.2 earthquake that occurred on 2002 October 24 in the northern part of Lake Kivu (Fig.…”

Feasibility Study of Community Earthquake Warning System Proposed for Mbeya City and Surrounding Regions

“…This region is part of seismically active region, the Western Rift Valley of Africa (WRA), a branch of East African Rift Valley system (EARS) where most recent strong earthquakes with some observable impacts to the communities have been observed [6]- [11]. The proposed CEEWS in this region aims at providing seismic protection to several urban settlements or population centers from earthquakes that may originate from the Lake Tanganyika and Lake Nyasa seismic sources.…”