Mass Wasting in Colombia

Landslide Mocoa April 1, 2017

Colombia is one of the most landslide-prone places in the world, with mountains, volcanoes, earthquakes, weathering and an intense rainy season all combining to create a terrain very susceptible to mass wasting. A majority of the landslides that occur in Colombia are in the mountainous western region of the country (as you can see in the image below from NASA's Disaster Program).

          A recent and devastating example is the 2017 Landslide that occurred on the first of April in Mocoa, Putumayo. Heavy rains triggered the flash floods and landslides that killed 254 people, injured 332, and left 70 missing. Soldiers, police officers, and red cross members worked side by side with the citizens to try to rescue survivors. Many were left with nothing, their houses and livelihoods destroyed. The government has spent hundreds of thousands of dollars on temporary housing for displaced peoples. This catastrophe is remembered as the third largest in Colombian history. 

Mudslide Mocoa April 1, 2017

In Colombia triggers for mass wasting will always exist and there is very little humans can do to stop landslides. There are, however, ways to mitigate the effects. Better city planning, early warning systems, and not building near danger zones would help prevent disasters. According to a 2006 report from the International Association for Engineering Geology and the Environment, "The Colombian government implements landslide monitoring, mitigation and stabilization programs. These include improved methods for mining subsidence prediction, better building control, improved engineering practice and communications. With landslide hazard mapping, risks and vulnerability maps are now available for major urban areas." However, it tends to be the poor and marginalized groups that live in the areas most susceptible to mass wasting, in pop-up towns on steep ridges on the out-skirts of cities. These buildings are usually built unofficially and out of code and are very susceptible to damage from mass wasting. Every year an average of 100 Colombian citizens die from landslides and there is no evidence of this slowing down over the years. The government has been working since 2011 making reforms to environmental management, but they have failed to enact anything yet.
There do seem to be private systems of warning though. For example, one may sign up for notifications for the latest weather hazards through a Colombian service provided by IDEAM (Instituto de Hidrología, Meteorología, y Estudios Ambientales) online and with an app called Mi Pronóstico which provides updates twice a day for all the regions of Colombia and provides emergency alerts.

April 19, 2017 Manizales 

Below are some interesting papers I read in my research that may be of interest.

https://www.issmge.org/uploads/publications/1/32/1994_06_0013.pdf
https://www.alnap.org/system/files/content/resource/files/main/iaeg-112.pdf
https://thebogotapost.com/mocoa-preventing-future-disaster/21536/

"Los Volcanes Dormidos"

http://www.astronoo.com/images/volcans/volcans-colombie.jpg

            There are 15 volcanoes in Colombia that are considered active with the most recent eruptions occurring at Galeras in 2014 and Nevado del Ruiz in 2012. As you can see from the image above they follow a line parallel to the plate boundary to the west and the Andean Mountain Range. The volcanoes in Colombia are part of a longer line of volcanoes, the Andes cordillera, that stretches from Argentina to Colombia. 

http://volcano.oregonstate.edu/oldroot/education/vwlessons/volcano_types/subd1c.gif

           These volcanoes are created through the subduction of the oceanic Nazca Plate beneath the continental South American Plate. The oceanic plate contains molecules of water and mineral deposits. When the oceanic crust melts it creates magma with a high volatile content. The resulting volcanoes that are formed along this subduction zone are stratovolcanoes. These volcanoes have more explosivity because when the eruption occurs the pressure that has built up with the volatiles is released. These volcanoes have more viscous lava that can not travel very far before cooling and becoming solid, therefore, these volcanoes have a cone shape and can create very high mountain ranges. The average height along the Andes Cordillera is 4000m with it's highest peak at 6962m.

The Nevada de Ruiz 1985

https://mellyrocks.files.wordpress.com/2015/10/nevado-del-ruiz-1.jpg

https://mariannestrassle.files.wordpress.com/2014/03/armero.jpg

                In 1985 one of the most devastating volcanic eruptions for the country of Colombia transpired in the Nevado del Ruiz, which stands at 5300m tall and is covered with glacial ice.  When the explosion occurred, glacier melts mixed with the mud creating a massive lahar that engulfed part of the town of Armero the night of November 13,1985, killing nearly 20,000 of the 29,000 inhabitants of the city in their sleep. The mud was so viscous that it was nearly impossible to provide relief to the remaining citizens. The world remembers the video and images of Omayra Sánchez seen, a 13 year old girl who died slowly in the viscous mud unable to be rescued.

https://youtu.be/ufbYv3SMdOE?t=74

             In total 23,000 people died and around 5,000 were injured. Unfortunately this catastrophe was made worse by the fact that this event was predicted by geologist that alerted the authorities and media but the people did not realize the real danger. There was also a strong storm the same day of the explosion that inhibited communication and most people stayed in their homes as they were instructed. Evacuation maps were made but they were poorly distributed. Because of this event, the people of Colombia have learned a hard lesson about the "volcán dormido" in their midst. This means "sleeping volcano" and the saying comes from the fact that stratovolcanoes can stay dormant for a long time before exploding, like this one did, for 69 years. The Colombian government has now set up a specialized office that promotes natural hazard awareness and are working with the US government to provide resources to better prepare and respond to natural hazards such as these. The volcanoes are being monitored everyday. In addition to this, many cities near the volcanoes have their own programs to raise awareness and educate people with disaster plans.