Smart Art: Earth Science

Earth Science Introduction

Earth science is the study of earth structures and phenomena, and includes the study of the origin of those structures and phenomena plus the origin of the earth itself.

You can break earth science down into general branches of climatology and meteorology (air), geology (land), and oceanology (water) Notd that oceanography is the mapping of the oceans, not the scientific study of the oceans. Because earth science also includes the study of earth origins, astronomy overlaps with earth science. The area of overlap is a specialty discipline in itself.

One of the fundamentals of earth science is the ability to say precisely where a given feature is. Anyone who's used a desktop globe is familiar with latitude and longitude, and those are the axis of the grid system used to denote locations on earth. So we say an object is at a given latitude and longitude. If it's moving, we might want to also note its direction of movement (something else earth scientists do routinely). For most areas of the earth, we note motion in relation to magnetic north or south. However, as we near the poles this doesn't work so well. Above certain latitudes, for example, ship navigators do not rely on magnetic readings.

When looking at earth features from a distance, say arriving here from some other planet, we would notice the topography (mountains, for example) and the landforms (continents). Both of these are always changing, and have changed dramatically over the eons. Human life is so extremely short compared to geological time that what we see appears to be stable. For example, the land mass of South America looks the same to us as it did to our great grandparents. But it does not look at all as it did 30 million years ago (a timeframe that still is short compared to the age of the earth).

The landmass change occurs due to a complex mix of natural phenomena, including:

• Continental drift. Continental plates move and one will push under another, eventually being recycled into the earth's mantle. The Himalayan mountain range (which includes Everest and K2) exists because the Indian subcontinent is pushing under the Asian continent and causing the edge to push up. So we get mountains from continental drift.
• Volcanic action. All the new mantle creates pressure. We get volcanoes. Iceland and Hawaii are examples of features resulting from this action. So we also get mountains from volcanic action.
• Erosion. Just as Congress wears us down with new taxes, so does rain wear down mountains. In the United States, we have two interesting examples of this. The Appalachians are old mountains, and have been worn down for millions of years. The Rockies are much younger, and thus have not endured as much erosion. Their peaks are much higher than those of the Appalachians, but eventually both ranges will disappear into the mantle. Both ranges were created by continental drift and will be destroyed the same way (if erosion and mining don't destroy them first).
• Runoff. Take a look at the USA map, around the Gulf area. That entire delta is an example of the deposits of erosion. All that eroded mountain mass had to go somewhere.

Charting and documenting the existing landmasses, rivers, oceans, and other features is the concern of a huge body of earth science called cartography. One of its big challenges is accurately representing a 3D image in two dimensions. Carefully remove half the peel of an orange so it's intact. Use a marker to write your name on it, or if you're really good draw a picture of someone on it. Now flatten the peel out and see how the words or image distort. You can also compare any paper map to any globe to see what the problem is.

Now you have an introduction to earth science. Since you live on earth (we presume), this topic should matter to you. Beyond being important because a rigorous study helps make you an informed person, the study of earth science is fun and interesting.

Not to disparage the scientists who make this their life's work, but many of them are still kids at heart. Their work involves the same fascination and natural curiosity they had as kids, and this drives them to continue in their chosen field (they don't do it for the money, though some are reasonably well-paid). We can all be thankful for this, as it adds to the richness of the human experience in many ways.