Lake Nyos 1986 Disaster Researchers Jillian Malone Jon

Lake Nyos: 1986 Disaster Researchers: Jillian Malone, Jon Meier, Nolan Nguyen, Kristen Way

Geography: - Region: NW Cameroon - Location: 300 km from the capital Yaounde and 50 km from the border of Nigeria - Topography: OKU Volcanic Field - Scoria cones and maars - Area: 1. 5 square km - Depth: 200 m

Limnic Eruptions

Cause: - CO 2 escapes from underground chimneys - Stratified layering - Co 2 trapped under extreme pressure - Overmixing and sudden release of CO 2

Effect: Diagram showing the Lake Nyos disaster. Step 1: Before the , CO 2 accumulates at the bottom of the lake. Step 2: After the earthquake, CO 2 bursts forth and flows into the valleys.

Lake Nyos Following Limnic Eruption: BEFORE: AFTER :

1986 Disaster

Overall Analysis of the Disaster ● Lake Nyos released 1. 2 km 2 of CO 2 into the atmosphere ● Large 50 m thick cloud of CO 2 rose from the lake and engulfed the 3 villages of Nyos, Subum, and Cha ● Immediate death to 1, 700 people and 3, 000 cattle ● Injuries included: epidermal burns, paralysis, and respiratory problems ● Cause: Internal wave? Seismic activity? Landslide? Flooding?

How Resources Were Deployed ● Lack of documentation of what was done after the disaster ● Waited several days for first responders to arrive ● 7 government refugee camps set up for 4, 434 residents ● Inappropriate donations, poorly handled, unevenly distributed ● 3 degassing pipes inserted into Lake Nyos

Cascade Events Affected social aspects and the economy rather than physical events ● Psychosocial: ○ ○ Sudden death of family members was traumatic Displacement from ancestral land into resettlement camps disrupts community, social networks, and cultural identity ● Economical: ○ ○ ○ Population dependent on agriculture Affected beef supply in the North West Region of Cameroon Even though crops were unaffected, they were abandoned when moving to resettlement camps

Those at Risk ● ● ● Children of pre-school (1 -4 years) and of school age (5 -9 years) Children born in camps without one or both parents; orphans Injured/hospitalized Nursing and pregnant mothers Homeless

Media ● Inconsistencies in reports of the incident ● 40 dead⇒ 300 dead⇒ 2, 000 dead and 20, 000 displaced ● 1. 5 billion FCFA (~$3 million) from local and foreign donors in cash donations ● Donated material aids worth ~$800, 000 ● No reports address long-term effects and needed assistance for survivors

Recovery Efforts ● Permanent structures in resettlement camps ● 2000 - Nyos Monoum Degassing Project is initiated by the Cameroon government, along with an advisory committee financed by France, Japan, and USA ● 2006 - rehabilitation of Lake Nyos and resettlement of the local population ○ ○ Estimated cost: 7. 4 billion FCFA Physical risk reduction measures: 6. 6 billion from the project

Lake Nyos: Today

Current Mitigation Efforts ● Different solutions to this hazard investigated by Jack Lockwood American team: ● Move population of the living 200 km downstream ● Remove first 40 m of water in lake Nyos ● Break dam ● Dig tunnel 65 m under present water level and add valves ● Jet-grouting technique ● Degassing

Current Situation, Possible Future Disasters ● Problems removing CO 2 ● Natural dam at the northwestern flank is likely to rupture ● Geologic activity from the Cameroon Volcanic Line could cause another eruption

Resettlement Camps Recovery ● 20% of households have returned illegally ● Slow recovery of both the population and the livestock ● Government still hasn’t fulfilled many promises made to help with long-term recovery Rates in Resettlement Camps in 201 3 Household size 35% Large ruminants 39% Small ruminants and pigs 11% Small livestock 33% Data from Balgah and Buchenrieder 2013

Lake Nyos Disaster Summary ● High concentrations of CO 2 in the lake due to outgassing from underground chimneys ● Sudden eruption of CO 2 killed 1, 700 people and 3, 000 livestock ● Survivors still displaced in resettlement camps ● Many external factors can trigger a limnic eruption ● Local population still not fully recovered from the disaster ● Degassing process is slow and expensive

References Bang, H. N. (2012). “Disaster Management in Cameroon: The Lake Nyos Disaster Experience”. Disaster Prevention and Management: An International Journal, 21(4), 489 -506. Balgah, R. Buchenrieder, G. (2014). The Impacts of Natural Disasters on Smallholder Agriculture in Rural Cameroon. American Journal of Experimental Agriculture, 4(3), 233 -243. Buchenrieder, G. , Mack, C. , & Balgah, A. (2017). Human Security and the Relocation of Internally Displaced Environmental Refugees in Cameroon. Refugee Survey Quarterly, 36(3), 20 -47. Kling, G. W. , Clark, M. A. , Compton, H. R. , Devine, J. D, Evans, W. C. , Humphrey, A. M. , Koenigsberg, E. J. , Lockwood, J. P. , Tuttle, M. L. , & Wagner, G. N (1987). “The 1986 Lake Nyos Gas Disaster in Cameroon, West Africa”. Science, 236(4798), 169 -175. "Lake Nyos (1986)". San Diego State University. March 31, 2006. Retrieved December 01, 2018. Othman-Chande, M. (1987). “The Cameroon volcanic gas disaster: An analysis of a makeshift response”. Disasters, 11(2), 96 -101. Ngwa, E. M. (1992). “Responding to Unmet Food Needs of Displaced Persons or Refugees: A Case Study for New Approaches in Kousseri Town and Nyos Area of the Republic of Cameroon”. Geo. Journal, 24(2), 323 -330. Rodrigue, C. M. . (2018). Group Project Guidelines [Cascade Events]. Retrieved December 04, 2018. http: //web. csulb. edu/~rodrigue/geog 458558/groupreport. html. Tchindjang, M. (2018). “Lake Nyos, a Multirisk and Vulnerability Appraisal”. Geosciences , 8(9). doi: https: //doi. org/10. 3390/geosciences 8090312