Why is it Difficult to Notice Mountains Getting Bigger or Smaller?

Have you ever wondered why it is so difficult to notice whether mountains are getting bigger or smaller over time? The answer lies in the gradual and subtle nature of geological processes that shape our landscapes.

Understanding the Geological Processes

There are two primary processes at play when it comes to the growth or shrinkage of mountains: uplift and erosion.

Uplift

Uplift refers to the process where mountains rise due to tectonic activity. This is a relatively slow process and, over short periods, changes are not easily noticeable. Uplift is a result of tectonic plates colliding with each other, pushing the land upward to form mountains. While these processes continue, the changes are so gradual that they are difficult to perceive without scientific measurement tools.

Erosion

Erosion, on the other hand, is the wearing down of mountains. This process can be quite visible and is the reason why we often see mountains shrinking over time. Erosion occurs due to wind, water, ice, and even human activities. For example, the constant force of water breaking down rocks on a scree slope, or landslides caused by rain, can make mountains visibly smaller in a matter of days or years. This is easier to observe and measure because erosion is a more active and rapid process compared to uplift.

Observing the Effects of Erosion

If you happen to be above tree level on a scree slope, watching the sun shine directly on frozen rock faces, you will see how erosion occurs. These rock faces are constantly breaking apart due to thermal expansion and contraction, water infiltration, and gravity, leading to tiny and sometimes not-so-tiny pieces of rock falling away. Over time, this accumulation of rock debris forms scree slopes, which are a direct result of erosion.

Patient Observation

While the process of erosion can be observed over a shorter period, noticing the gradual changes caused by uplift is a different matter. If you are truly dedicated, patience is key. By observing a mountain for a week or more, you might begin to see subtle changes. For instance, with consistent observation, you might notice a small portion of a mountain crumbling away or complete a tiny landslide. However, these changes, while observable, are often too gradual to be noticed on a day-to-day basis without careful attention.

Examples of Rapid Changes

Contrarily, it is not difficult to see changes in mountains if they are caused by more rapid processes such as erosion from landslides or human action. As mentioned, landslides can happen quite quickly and are often visible in the form of newly exposed rock faces or changes in the topography of the mountain. Similarly, human activities such as deforestation, mining, or construction can significantly alter the shape of a mountain in a short period, making the changes more noticeable.

Volcanic Activity

Another context where noticeable changes can occur is through volcanic activity. The release of lava or ash from volcanoes can cause mountains to grow larger almost immediately. This is a result of the addition of new material to the landscape. For instance, when a volcano erupts and deposits lava, the mountain can practically grow taller right before our eyes. The summit of the mountain becomes a new and distinct feature, clearly visible in the landscape.

Welcome to the Discussion

If you have experienced observing mountains changing over time or have any stories to share, we would love to hear from you. Leave a comment below and join the conversation!