Potential hazards of continued dome growth on Colombia's Nevado del Huila

Earlier today, Dr. Boris Behncke posted a link to some fascinating images of the dome growing at the summit of Nevado del Huila (see below) in Colombia. The volcano started erupting again in 2007 after what is thought to be almost 500 years of quiet. The eruptions since 2007 have been relatively passive - VEI 2-3 explosions and dome growth. However, in 2008, the volcano produced a 50,000 feet ash plume that lead to "one of the world's largest" lahars that did cause some fatalities (but nothing compared to the 1985 lahars from Nevado del Ruiz that killed over 20,000, a testament to the improvements that INGEOMINAS has made in volcano monitoring). Huila, in fact, produced its deadliest volcanically-related event when it wasn't erupting - in 1994, an avalanche and lahar from the volcano swept down the Rio Paez valley to the south, killing hundreds and leaving over 20,000 people homeless. This event was not triggered by an eruption but rather a M6.4 earthquake causing the loosely-consolidated volcanic debris to slide down the volcano, likely a common event in volcanic terrains.


A view of the summit area of Nevado del Huila in Colombia showing the growth of the summit dome. Image by INGEOMINAS, taken on January 25, 2011.

The images posted by INGEOMINAS in last January show a steep-sided dome growing at the summit of Huila. IR images of the dome show that the material, like andesite or dacite, is hot (not surprisingly) and the dome appears to be continuing to grow. This means that the threat of a dome-collapse pyroclastic flow (or block-and-ash flow, similar to those at Soufriere Hills) will rise as the dome's sides steepening. Now, looking at a map of the region near Huila, we can see that it is surrounded by National Park, so in all likelihood, pyroclastic flows wouldn't be a direct danger to surrounding communities. However, as the 1994 and 2008 lahars show, if the ash and debris from potential pyroclastic flows become remobilized or mix with water/snow, lahars are likely to be the product*. 

The current status at Huila is Yellow Alert status, which suggests continued unrest at the volcano. Seismicity and increased fumarolic activity at the summit called for brief evacuations near the volcano, but it appears that the geologist at the Popayan Volcano Observatory don't think the activity is abnormal: "We conclude that the volcanic phenomenon presents fluctuations characteristic of the current activity level." However, if dome growth continues, the new threat might come from a collapse rather than an eruption. Remember, you can see the activity at Huila on one of the two webcams pointing at the Colombian peak.

*Note: Normally, John Seach is an excellent source for volcano information. However, I have never heard of lava flows, especially andesitic or dacitic, moving at 40 km/hr like he mentions in his page for Huila. I consider this questionable unless I (or you) can find any corroborating information). My guess is he means lahars (?)

Top left: Another view of the summit of Huila, showing the new dome on January 25, 2011. Image by INGEOMINAS.

'Upstreamism': Your zip code affects your health as much as genetics

Upstreamism advocate Rishi Manchanda calls us to understand health not as a "personal responsibility" but a "common good."

Sponsored by Northwell Health
  • Upstreamism tasks health care professionals to combat unhealthy social and cultural influences that exist outside — or upstream — of medical facilities.
  • Patients from low-income neighborhoods are most at risk of negative health impacts.
  • Thankfully, health care professionals are not alone. Upstreamism is increasingly part of our cultural consciousness.
Keep reading Show less

Elizabeth Warren's plan to forgive student loan debt could lead to an economic boom

A plan to forgive almost a trillion dollars in debt would solve the student loan debt crisis, but can it work?

Photo credit: Drew Angerer / Getty Images
Politics & Current Affairs
  • Sen. Elizabeth Warren has just proposed a bold education reform plan that would forgive billions in student debt.
  • The plan would forgive the debt held by more than 30 million Americans.
  • The debt forgiveness program is one part of a larger program to make higher education more accessible.
Keep reading Show less

Banned books: 10 of the most-challenged books in America

America isn't immune to attempts to remove books from libraries and schools, here are ten frequent targets and why you ought to go check them out.

Nazis burn books on a huge bonfire of 'anti-German' literature in the Opernplatz, Berlin. (Photo by Keystone/Getty Images)
Culture & Religion
  • Even in America, books are frequently challenged and removed from schools and public libraries.
  • Every year, the American Library Association puts on Banned Books Week to draw attention to this fact.
  • Some of the books they include on their list of most frequently challenged are some of the greatest, most beloved, and entertaining books there are.
Keep reading Show less

Supreme Court to hear 3 cases on LGBT workplace discrimination

In most states, LGBTQ Americans have no legal protections against discrimination in the workplace.

(Photo by Andres Pantoja/SOPA Images/LightRocket via Getty Images)
Politics & Current Affairs
  • The Supreme Court will decide whether the Civil Rights Act of 1964 also applies to gay and transgender people.
  • The court, which currently has a probable conservative majority, will likely decide on the cases in 2020.
  • Only 21 states and the District of Columbia have passed laws effectively extending the Civil Rights of 1964 to gay and transgender people.
Keep reading Show less