Altitude Sickness: How mountains tell you they don’t want to be climbed

Mountains are a wonderful thing. In fact, they are the preferred geological formation of the Sketchy Science team. That is why we have spent the past several weeks on and recovering from a research expedition to some of the highest peaks North America has to offer: the 14,000 foot peaks of Colorado’s Rocky Mountains. While peaks in Alaska, B.C., and the Yukon attain higher elevations, none can rival Colorado for sheer accessibility.

Accessibility is what you need if you want to study and report on altitude sickness. With this in mind, our writer (me) and illustrator loaded up our respective vehicles and drove, with our romantic partners and two canine companions, from our elevations of residence (0 feet/m and 1,000 feet/300 m respectively) to the highest city in the continental United States: Leadville, CO (10,200 feet, 3,108 m).

Altitude impacts the human (and canine) body in a number of important ways, but they all stem from the fact that the air at altitude is less dense. At low elevations air is compressed by the weight of all the air above it. As you move towards the stratosphere, the column of air you exist in becomes shorter (there is less air above you), and so the weight is lessened and particles have more freedom to stretch out from one another. It isn’t that there is less oxygen in the air (the rate is a pretty constant 21% regardless of altitude), but in the mountains there is more space between oxygen molecules.

Aside from the relatively straightforward problem of your body not being able to get enough oxygen, the air at altitude is also drier. This causes your tissues to lose water rapidly to the air. Your body responds by constricting blood vessels and holding on to water and sodium in areas like the kidneys. The end result is higher blood pressure, a more rapid heartbeat, and an imbalance of moisture and salts.

At altitudes as low as 5,000 feet/1,524 m, this can lead to disturbed sleep as your body struggles to balance oxygen and carbon dioxide by interrupting your breathing during the night. The upshot is you are unrested as you head out exploring the mountains and you make your other symptoms (if you have any) worse. During the day, your body compensates for thin air by breathing more rapidly, leading to headaches, nausea, and dehydration.

At extreme altitudes (above 18,000 feet/5,486 m), the effects on your body can be life-threatening. The two most dangerous conditions are High Altitude Pulmonary Edema (HAPE) and High Altitude Cerebral Edema (HACE). Both are the result of fluid leaking from your constricted blood vessels and collecting in your tissues. With HAPE, the fluid gathers in your lungs. You struggle to breath and can effectively drown without ever touching water. Unbelievably, HACE is worse as the fluid gathers in your brain. The increased pressure in your skull leads to confusion, lack of coordination, and sometimes coma and death.

Curiously, altitude doesn’t hit everyone the same way and it is tough to predict who will struggle and who will thrive where the air is thin. Marathon runners are no better off than habitual couch potatoes. If the symptoms are mild (headache, nausea, fatigue), then they generally fade with more time spent at altitude – this is called acclimatization. With rest and plenty of water you will start to feel better in as little as 12 hours. The US Army reports that the respiratory element of acclimatization is 70-80% complete within 7 to 10 days. Between 14 and 30 days you are 80 to 90% acclimatized. Total acclimatization can take months or years, though.

If, like us, you are not in immediate danger and have more ambition than common sense, you can find help from over the counter drugs like ibuprofen or by eating foods that are high in carbohydrates like pasta and bread. You can also prevent altitude sickness by spending a night at lower elevation before going higher and by ascending in stages with rest days to let your body get used to the new environment more gradually.

In the end, the hardest part about exploring the high-country is balancing respect for your health and the power of nature (storms, avalanches, and stuff) with the urge to be a hero. Pain is temporary and glory is forever, but death is even more forever. So be safe and be responsible, but enjoy the mountains and the freedom they bring.

Climate or Climb It? How changing weather builds mountains

It is easy to think of mountains as permanent features of a landscape. Don’t do it. That is what they want you to do. Let your guard down for one second and those craggy jerks will be on you like white on rice. Mountains change and they do it constantly. We all know about plate tectonics and how ancient sea floors are now some of the loftiest places on the planet. But did you know that climate can also shape mountains?

  

Recent research from the University of California at Berkley has revealed that California’s already substantial Sierra Nevada Mountains have risen 10 millimeters in the past 7 years. You might expect that this is due to things like earthquakes and tectonics plates crashing into each other, but that is only partly the case. The researchers have also suggested that California’s ongoing and increasingly severe drought has been causing the peaks to shoot upward.

The thing about the Earth’s crust is that it’s a lot more like a mattress than it seems. Put some weight on it and it will dent pretty easily. Take the weight off and watch it spring back up (if you have a few decades to spare). Much of North America’s crust is still rebounding upward in response to the removal of the weight of glaciers from the last ice age, a process called isostatic rebound. In California, glaciers are generally hard to come by, even during an ice age. The uplifting there is the result of water loss in the soil.

It may not seem like it it, but water is massively heavy stuff. It is even heavier than ice, which is why the "rocks" in your scotch float. A one meter by one meter by one meter cube of water weighs a ton. That means the bed of an average pickup truck could hold several thousand pounds of water. Imagine how much the rain water that falls on a mountain range in a year weighs and you can begin to understand why a long running drought might cause mountains to rise.

As water fluctuates and the Earth’s crust reacts, we can get into some pretty hairy situations. A growing body of research is providing evidence that changing rainfall and ice-melt patterns associated with climate change might even cause volcanoes to become more active (Capra, 2006; Deeming et al., 2010). Your classic stratovolcano is just a mountain with a lot of internal pressure. As the amount of ice or water on the overlying mountain changes, the magma chamber underneath can become unstable. When enough weight has been removed the effect is like taking the cap off a shaken up bottle of coke.

Even if the magma chamber doesn’t blow its top, melting ice can destabilize the soil in a slope and cause landslides. The massive landslide in Washington State on March 22, 2014 that killed 41 people came after a period of intense rain that weakened the slope which eventually failed.

Mountains are pretty uncool in that way. They can sit there for millions of years looking all rock-solid and majestic. They watch and wait as we build towns at their bases so we can enjoy the view, going about their natural processes of erosion and uplift at a pace that the human eye just can’t observe. Then one day, either because it has rained too much or not rained enough they are capable of kicking things into overdrive. The lesson in all of this? It’s okay to make friends with a mountain. You can even hang out from time to time. But don’t for a second think you can trust them. They’re more lively than they seem.

References:

Capra, L. (2006). Abrupt climatic changes as triggering mechanisms of massive volcanic collapses RID C-2371-2011. Journal of Volcanology and Geothermal Research, 155(3-4), 329-333. doi:10.1016/j.jvolgeores.2006.04.009

Deeming, K. R., McGuire, B., & Harrop, P. (2010). Climate forcing of volcano lateral collapse: Evidence from Mount Etna, Sicily. Philosophical Transactions of the Royal Society A-Mathematical Physical and Engineering Sciences, 368(1919), 2559-2577. doi:10.1098/rsta.2010.0054