Elbrus air pressure
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The main difficulty that climbers face during their ascent to Mount Elbrus - regardless of route, weather, experience or season - is the influence of altitude and low oxygen level in the air.
The influence of the altitude factor on the human body is that strong due to the unusually low level of atmospheric pressure and, accordingly, the low level of oxygen content. The material presented below is about how the level of atmospheric pressure affects the oxygen content in the air, as well as about the peculiarities of the influence of altitude on the human body at different geographical latitudes.
Let's figure it out from the very beginning. What is atmospheric pressure? Let's imagine that we live at the bottom of an ocean of air, and the thickness of the atmosphere above us is approximately 1000 km. The entire air shell of the earth is subject to the law of universal gravitation and, therefore, has mass. The closer to the surface of the earth (which is the bottom of the air ocean), the denser and “heavier” the atmosphere becomes - the greater becomes the mass of the air column.
Since our usual habitat is the surface of the earth - the majority of the population lives between 10 and 500 meters above sea level, the atmospheric pressure at this level is familiar and comfortable to us.
The proportional amount of oxygen is directly related to air pressure, and is approximately 21% of the total volume. Oxygen is vital for all the processes occurring in our body - therefore, when gaining altitude while climbing high mountains, it is the lack of oxygen that causes many difficulties and problems.
To monitor changes in the air pressure, several conventional measurement systems have been adopted - the usual scale for us is millimeters of mercury. The norm for 99% of the world's population is a pressure of 760 mm, which corresponds to altitudes of 0-100 meters above sea level.
As you climb above the surface of the earth, the atmospheric pressure decreases - so, at an altitude of 1000 meters, the atmospheric pressure will be 675 mm, and at the altitude of the summit of Mount Elbrus that will be 389 mm, which is almost half of the usual norm, including the proportional oxygen content.
The atmospheric pressure on the top of the highest mountain of the Earth - Mount Everest - is 265 mm (30% of the norm) - life activity at such altitude without additional instruments is far beyond normal human capabilities. Although the facts of oxygen-free ascents to Mount Everest indicate that the real capabilities of our body are much wider than is commonly believed.
The capabilities of the human body in terms of adaptation to external conditions, including the oxygen content in the air, are quite extensive. For example, it is argued that the upper ceiling of human life is an altitude of approximately 5500 meters - at this level some high-mountainous peoples in the Himalayas and Andes live all their lives.
Altitude above 6,500 meters with an atmospheric pressure below 350 mm and an oxygen content of approximately 40% of normal are considered uninhabitable. A person, without special means of supporting life, can stay at such altitude for a very limited time.
This altitude level is called the “Death Zone” - at this altitude, full acclimatization is impossible, and rapid irreversible changes occur in the body. Depending on preliminary preparation and acclimatization, a person can survive at such an altitude from several hours to several days.
All the figures and calculations presented above illustrate only the general principle of the relationship between altitude, atmospheric pressure and oxygen content in the air. This rule cannot be applied universally to all the mountains of the Earth, since the oxygen content at the same altitudes, but at in different geographical latitudes, will differ significantly.
The fact is that the air shell of the earth does not correspond to the shape of the globe - it is, as it were, flattened - the greatest thickness of the air layer corresponds to equatorial latitudes, and towards the poles the thickness of the atmosphere decreases.
Accordingly, the influence of altitude will be more noticeable the further north or south we move from the equator. For example, the Mount Kilimanjaro climb, a 5895 m high peak in Africa located just 342 km from the equator, can be done much more comfortably than climbing Mount Elbrus (5642 m high and 4810 km from the equator).
The lack of oxygen and the feeling of the influence of altitude on Mount Elbrus is felt much more strongly.
A general rule in mountaineering is that, given equal altitudes, mountains become harder to climb as they are located further from the equator - this factor should be taken into account when choosing a mountain and acclimatization schedule for those planning to take up mountaineering and choosing their first truly high mountain.
Based on this rule, the difficulty of the climbing programs in our collection is determined not only by the actual altitude of the mountains, but, to a greater extent, by their geographical location. In accordance with these features, an appropriate acclimatization schedule is built, which is necessary for a safe ascent to a particular peak. In order to maximize the chances of a successful ascent and reduce the risk of possible health problems.
The author of the texts and photographs Alex Trubachev
Your professional mountain guide for Mount Elbrus and other mountain climbing routes in Caucasus
MCS EDIT 2024