Main Information
LCI: NGA1711131322
The Sierra Leone mudslide of August 14, 2017, took place in the Regent area of Freetown on the steep slopes of Mount Sugar Loaf. Sugar Loaf forms a part of extensive and forested highlands south of the the city. The city of Freetown and its suburbs have grown in recent times to almost encircle this roughly elliptical highland region. Intruding these rocks are isolated basic intrusives of Triassic to Early Jurassic age. The most prominent of this is the Freetown Layered complex which forms the extensive highlands which Freetown surrounds and which Mount Sugar Loaf is a part of. The Freetown layered complex consists of troctolitic gabbro and anorthositic rocks dated 193 Ma. This intrusion formed part of the basic volcanism associated with the initial rifting stage of the opening of the Atlantic Ocean. The hills of the Freetown Layered Complex show major NE-SW and minor NW-SE trending lineaments. These lineaments are most likes fracture zones within the rocks of the Freetown complex. The lineaments clearly control the drainage and the erosion of the hills in the region. One of these structurally controlled NE-SW streams cuts through the Regent area where the mudslide occurred.
Location
City / District: Freetown
Province: Western Area
Country: Sierra Leone
Latitude: 8:26:0 N
Longitude: 13:13:18 W
Reporter
Reporter 1: Ogbonnaya Igwe
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Landslide Type
Material: Earth
Movement: Flow
Velocity (mm/sec): Rapid (5×10⁻¹ - 5×10¹ )
Depth (m): Moderate-Shallow (5 - 20)
Slope (degree): Steep (30 - 40)
Volume (m³): Large (10⁶-10⁷)
Date of Occurence
Date of Occurence: 08/14/2017
Other Information
Land use (Source Area): Forest, River
Land use (Run-out/deposition area): Urban area
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Triggering Factor: Rainfall
Death(s) & Missing: 1000
Houses and other structural damage: Extensive
