Poás Gets Our Attention!

My back deck overlooks the Central Mountain Range that forms the northern boundary of the Central Valley where San José is located. When I first requested my place in early 2016 sight unseen, I asked for a unit overlooking these mountains, because their distinct shape has always represented “home in Costa Rica” to me. Little did I know I was getting practically a front row seat for the reawakening of one of Costa Rica’s most famous volcanoes, the Poás.

If you’ve ever been to Costa Rica, chances are excellent you’ve been up to the Poás, because until this last April, it has been one of the most popular tourist destinations in the country.

I’d been looking at these mountains all my life and I had never seen them emit anything more than a rare puff of vapor. Around the 6th of April, I noticed the distinct smell of sulfur in the air, and the atmosphere seemed heavy with particulate matter that had a different look and feel from the occasional smog we see during a temperature inversion, or the ash clouds we occasionally experience from the Turrialba volcano.

Within days, visitors to Poás began to complain of feeling ill, and as a result, evacuations and park closings began. On Wednesday April 12, an explosion of rocks and water caused flash floods and mudslides (lahars) southwest of the crater as nearby rivers filled with sediment. The park was closed on Thursday, April 13 and warnings and evacuations of the area began in earnest.

Friday, April 14, 7:30 a.m. I was sitting on my deck having a leisurely cup of coffee while doing a little reading. And on this beautiful clear morning, I glanced up to see… the huge plume with which Poás announced its official awakening! Wow! What an awesome sight!


Poas erupts

The almost 10,000 ft. high ash and vapor plume was impressive, but not scary. Of course I can say that because I wasn’t in harm’s way. Plus, everything billowing out was mostly white, which indicated more vapor and less ash, meaning this was more bark and less bite; at least for now. I couldn’t hear anything if you’re wondering. It wasn’t like in the movies–I’m sure at the site it was hissing and bubbling and making all kinds of noise, but nothing alerted the rest of us further away.

Needless to say I started taking pictures for my family in the states and Facebook. It’s not every day you get to watch a volcano erupt from your deck! I think I said Wow about a hundred times in 5 minutes!

A few minutes later there was another eruption, and by now pretty much everyone within miles of the central valley was watching and sharing their experience on social media sites. Videos reveal cars pulling over by the side of the road during the peak of the morning rush hours. Shot below is a still from one video that went viral–I was unable to track down the original person to credit.

highway pic from video

The Turrialba, east of San José, has been erupting sporadically for several years, but now having two volcanoes erupting at the same time was just incredible! (Little did we know that Rincon de la Vieja would come to life a few months later, so now there are three!)


Two individuals captured amazing photographs that would become famous within hours. Scott Rovak, photographer, had just taken off on a flight out of San José that morning and caught a once in a lifetime moment, as the eruption billowed into the sky.  A few months later, Laura Barboza Rodriguez would capture both the Poás and Turrialba in a single image from her own flight.

Rovak and Barboza shots


This initial show would be followed by continuing eruptions nearly daily. June and July 2017 eruptions included reddish colored ash and respectable chunks of incandescent rocks. Unfortunately, I really can’t see any of this because the crater isn’t visible from the central valley where I am; only those situated to the north of it can see it. I have been lucky to see the occasional red reflections in the plumes at night or early morning hours, and I enjoy watching those through binoculars.

red sky poas

The chemical gases and the particles of ash create the perfect recipe for incredible red skies at sunset. I don’t have the knowledge to explain why this is so (perhaps some of you do), I only know it to be true.

Poás is approximately 34 miles north of San José near the western end of the Central Range. Visible from most of the central valley, the 8885 ft. high volcano had two crater lakes, the greater of which was notable for being one of the largest (a mile across!) and most acidic in the world.

The last time Poás really erupted was in 1956, so most Costa Ricans had not seen this highly visible volcano ever really do much. Not everyone even knew which peak was Poás, since it doesn’t have the typical cone shape. It has remained quietly active however, for hundreds of years. Every now and then (1969 &1987) it would huff and puff a bit as if to stretch and yawn before going back to sleep.

I lived a little closer to it between 1986 and 1996, and will never forget the night it produced some of the strangest sounds I had ever heard—something like a giant’s groaning or snoring that seemed to come from the bowels of the earth itself. We all expected an eruption, but none came. There were a few significant rumbles in 2014, but these were overshadowed by the newly awakened Turrialba volcano. I’ll get to that one in a separate post.

Magma has been detected and Poás’ sudden and accelerated return to an active eruptive state has resulted in increases in close monitoring of the area. Prevailing winds blow most of the ash and gases west and away from San José. At primary risk are those who live in the immediate vicinity, on the nearby rivers, or on the western side of the volcano. Whatever reaches me is so insignificant, it’s unnoticeable.

As I write this in September of 2017, Poás is still doing its thing, albeit not as grandly most days. One of the first things I do when I pull open my bedroom curtains in the morning is look to see if it’s clear or billowing vapor and ash. Its famous lagoon is gone and the crater has been totally transformed.

Experts believe the explosive eruption potential of Poás is high, but are hopeful that the continued emanations of steam and gases are helping minimize that danger. For now, the greatest losses have been economical, as national and international tourism to the Poás National Park has now been at a standstill for months.

Background about Costa Rica’s Volcanoes

Costa Rica is part of a land bridge between North and South America that owes it’s characteristic landscape to the volcanic “ring of fire” it rests on, and researchers have identified over 200 volcanic formations in our mountain ranges. Fortunately, the vast majority are from this land’s very ancient history, and although geologists aren’t all in agreement, the modern day tally stands at approximately 112 identifiable volcanoes, with at least half of these considered totally dormant with no detectable sign of ever returning to life. Geological research reveals that only 10 different volcanoes are likely to have erupted during the last 10,000 years, and these are the same ten considered active today.

Miravalles, Orosí, Barva, Tenorio, Platanar occasionally belch a bit of vapor and gases, but only Poás, Turrialba, Rincon de la Vieja, Arenal, and Irazú have erupted since the Spaniards first colonized the country approximately 500 years ago.

One way I keep myself informed of any significant developments is via the Volcanological and Seismological Observatory of Costa Rica (OVSICORI). While several other international agencies are closely monitoring all our active volcanoes, the above mentioned organization, affiliated with the National University of Costa Rica, usually provides the most up to date and comprehensive information.

I’ve included two links below for additional information and images.

As of this writing, Poás, Turrialba, and Rincón de la Vieja are in actual eruptive phases of activity. Rincón de la Vieja is hours north of San José. Turrialba and Poás are part of the Central Range—the mountains that form the northern limit of the central valley where San José is located. If you come to the capital, these are the two you’ll most likely see. Now, back to the other volcano in my back yard…

Volcán Barva


The Barva volcano is directly in front of me when I sit on my deck and is only about 12 miles away. The five peaks in the image above, and everything in between is Barva. Yes, roughly everything above the line of fog! It includes the three peaks to the right known locally as the “Tres Marías” and the two on the far left.

Barva is the largest volcano in Central America as far as area goes—over 575 square miles. It contains at least a dozen points of eruption or emanation, with many active fumaroles and thermal lagoons. It’s a sleeping monster that hasn’t actually erupted in at least 5,000-6,000 years, but is a quietly active volcanic structure. If it should decide to come back to life, well… I’ll be one of the first to know, for sure!


 Two Volcanoes in my Back Yard

Barva and Poas labeled

It’s pretty amazing to be able to say my view includes volcanoes even if it’s nothing special 99% of the time. The above photo shows you what I see most days. (I edited out the cell tower for this shot) Costa Ricans have been living alongside these giants for hundreds of years, and most of us go about our day scarcely remembering they’re here. But I had my moment of excitement, so forgive me when I shout, “I have volcanoes in my back yard!”

Pura Vida!


Note: Some areas around Poás, Turrialba, and Rincon de la Vieja remain off limits to visitors and hikers. Evacuations of the immediate areas around all the active volcanoes have taken place from time to time. Persons exploring the rivers or mountains in the affected areas are advised to check with authorities and heed their recommendations. Under no circumstances should you enter restricted areas of the parks. Just because there doesn’t appear to be any danger, it doesn’t mean there aren’t toxic fumes present. Risk of lahars may also be high.