Charles A. Heatwole

Article / Updated 03-26-2016

It would be great if you could go deep into the Earth and see what's going on, but that's impossible — despite what Jules Verne wrote. The average distance from Earth's surface to the center is 3,960 miles, and no human has ever come close. Several books and movies have portrayed such fanciful feats, but the truth is that people have barely penetrated the crust. Miners in South Africa have gone down about two miles; and if that's not the record, then the real one can't be much farther. So instead of going on a fantastic journey, you must settle for a diagram (as shown in Figure 1) based on informed speculation. Looking at it may cause you to wonder, "Well, if nobody's ever been down there, then how do you know what it looks like?" Great question! Here's the quick answer. Figure 1: A cut-away view of the Earth. Our understanding of Earth's interior rests on a combination of inference, analysis of alien objects, sound waves, and rocks and minerals. Alien objects are not UFOs, but rather meteorites and such that have fallen to Earth. These uniformly reveal a high percentage of iron. Because these alien objects are the result of the same process of planetary formation that produced Earth, the assumption is that the proportion of iron in these objects is probably about the same for planet Earth. That suggests an incredible amount of iron beneath your feet. Earthquakes produce sound waves. Over the past several decades, seismologists (people who study earthquakes) have placed within the crust hundreds of "listening devices" that record and analyze sound waves made by earthquakes. Some of these waves, it turns out, have peculiar characteristics: They cannot penetrate liquids, or liquids deflect them, or they travel at different speeds through liquids and through solids with different characteristics. Analysis of the tracks and characteristics of literally hundreds of such waves, plus the previous inference concerning iron, provide much of the input for Figure 1. Also, geologists have studied lots of rocks and minerals that have been thrust up through the Earth's crust. Analysis of these materials reveals a relative scarcity of iron, which suggests this substance must be concentrated deep within the Earth. The composition and temperature of Earth's interior are the reasons nobody has ever gone there and probably never will. Most of that realm is molten or almost molten. Thankfully, not only is it out of sight and out of mind, but also out of touch. Were it not for the insulating crust, life as we know it simply would not exist. Directly beneath the lithosphere lies the asthenosphere. Measured in the thousands of degrees Fahrenheit, its rock assumes a plastic, almost molten quality. Directly beneath the asthenosphere is a vast volume of somewhat stronger rock, and below that liquid iron of the outer core and solid iron of the inner core that is hotter still (as shown in Figure 1). Altogether, that vast volume of incredibly hot stuff is a powerful source of pressure — tectonic force. Indeed, it is mighty enough to create and rearrange continents, and in the process build mountains and cause earthquakes and volcano eruptions to occur. This knowledge has been available for only a couple of decades. But the idea of a force powerful enough to move continents has been around for centuries.

Article / Updated 03-26-2016

In geography, the world as a whole possesses a grid whose coordinates may be used to identify the absolute location of things. Indeed, that is why a Greek named Hipparchus invented the global grid some 2,200 years ago. As chief librarian at the great library in Alexandria, Egypt, Hipparchus compiled information about lands and cities all over the expanding Greek world. He saw the value of accurately locating objects on a map, but in those days that was easier said than done. Maps were notoriously inaccurate, due in good measure to lack of a systematic means of stating the location of things. So Hipparchus set out to rectify the situation and came up with the global grid that is still in use today (see Figure 1). Figure 1: The basics of the global grid. Avoiding gridlock Proper use of a grid coordinate system to state the absolute locations of things depends on a handful of prerequisites. Think of these as ways of avoiding gridlock: Familiarity breeds success. Knowledge of the naming and numbering of grid components is essential. If, for example, a stranger is not familiar with a city map, then telling her the hospital is at "the intersection of South 1st Street and West 1st Avenue" would have made no sense whatsoever. The same is true with respect to the global grid. That is, knowing how the lines are named and numbered is essential if you are to use the grid successfully. Unique components. Each line on the global grid must have a unique name. In a city map, for example, there must be only one road named South 1st Street, and only one named East 1st Avenue. If multiples exist, then more than one site could satisfy "the intersection of South 1st Street and East 1st Avenue." And that would rather defeat the concept of absolute location. No double-crossing allowed. Don't take that as a threat or accusation. What it means is that two lines on the global grid may cross each other only once. If they have multiple junctions then, such as the last point, there would be two or more intersections of, say, South 1st Street and East 1st Avenue.And again, that would defeat the concept of absolute location. Full names, please. You must use the full name of each line on the global grid. Again, the absolute location of the hospital is the intersection of South 1st Street and West 1st Avenue. Now suppose you had told that stranger, "The hospital's at the corner of 1st Street and 1st Avenue." Well, there may be several 1st Streets and 1st Avenues (South, North, East, West, what have you), so you may have several instances where a 1st Street crosses a 1st Avenue. Obviously, the potential for location confusion here defeats the purpose of absolute location. The remedy is to use the full name of each grid component. The naming game The global grid consists of imaginary lines of latitude and longitude (see Figure 1). Latitude lines go across the map — latitude comes from the Latin latitudo, meaning breadth, or the measure of the side-to-side dimension of a solid. Longitude lines run from top to bottom — longitude comes from the Latin longitudo, meaning length. This makes sense because when viewed on a globe, lines of longitude are generally lengthier than lines of latitude. The global grid contains a principal line of latitude (the equator) and a principal line of longitude (the prime meridian). All other lines of latitude and longitude are named and numbered respectively from these starting lines. It makes sense, therefore, that if you want to make like Hipparchus and draw a grid on a globe, then these are the first two lines you would draw. But where would you put them, and why? The equator Because Earth is sphere-like, no compelling locale cries out and says, "Use me to locate the equator!" So where to put it? Old Hipparchus might simply have said, "It's Greek to me!" and placed it anywhere. Instead, he wrestled with the challenge and came up with an ingenious solution. He knew that the Earth is sphere-like and that it rotates on an imaginary line called the axis. Look on a globe and you find two fixed points, halfway around the earth from each other, where the axis intersects the Earth's surface: the North Pole and the South Pole. So Hipparchus drew a line that ran all the way around the globe and was always an equal distance (hence, equator) from the two Poles. The result is a latitudinal "starting line" from which all others could be placed on the globe. The prime meridian The longitudinal "starting line" is called the prime meridian, which signifies its importance as the line from which all other lines of longitude are numbered. Locating this line proved more problematical than locating the equator. Quite simply, no logical equivalent of the equator exists with respect to longitude. Thus, while the equator came into general use as the latitudinal starting line, mapmakers were perfectly free to draw the longitudinal starting line anywhere they pleased. And that is what they did. Typically, mapmakers drew the prime meridian right through their country's capital city. By the late 1800s, lack of a universal prime meridian had become a real pain in the compass. International trade and commerce were growing. Countries were claiming territory that would become colonial empires. But one country's world maps did not agree with another's, and the international climate made it increasingly advisable that they do so. As a result, in 1884 the International Meridian Conference was convened in Washington, D.C., to promote the adoption of a common prime meridian. Out of that was born an agreement to adopt the British system of longitude as the world standard. Thus, the global grid's prime meridian passes right through the Royal Greenwich Observatory, which is in the London suburb of Greenwich, as well as parts of Europe, Africa, and the Atlantic Ocean. The British system was chosen largely because in 1884 Britain was the world's major military and economic power, and also had a fine tradition of mapmaking.

Article / Updated 03-26-2016

Language is arguably the most important of the cultural universals. This is not to question the significance of religion or other traits; but language is essential to communicating and sharing many aspects of culture. The standard first step in analyzing the geography of languages is to produce a map of them. For example, Figure 1 shows a map of where English is the primary language. Figure 1: The geography of English is shown by the dark shade. As shown in Figure 1, in Britain, Australia, New Zealand, Canada, and the United States, English is spoken by the overwhelming majority of the population. In other countries, English is spoken only by a minority, even though it may be an "official language." The "big picture" map aside, consideration of language affords opportunity to observe and apply diverse concepts of cultural geography. Diffusing languages The map of English-speaking countries is in large measure a product of cultural diffusion from Britain through its former colonies. The initial stage was largely limited to relocation diffusion. That is, large numbers of immigrants and officials moved from Britain to the colonies and, of course, took their language with them. Once there, they intermingled to different degrees with native peoples and non-English speaking immigrants, many of whom acquired English by contagious diffusion — contact with English speakers. English now enjoys the status of official language — the one in which government business is transacted and printed, as well as the language of publicly financed education — in virtually all of Britain's former colonies. In many cases, it is also the vernacular language — the one that is spoken by the people of a particular locality. But official and vernacular languages are not always the same in a given area or region. English, for example, is the official language of the United States and most Americans speak it, but literally millions of people living in ethnic neighborhoods, Indian reservations, and other enclaves across the land speak a different vernacular language. Look again at Figure 1 and you may get the impression that everybody in the United States, Australia, and New Zealand speaks English. Not so. People in parts of each country speak a different vernacular language. Many countries that are former colonies have adopted the language of the colonizer as their official (or co-official) tongue even though, in many cases, only a minority of the populace speaks it. Examples include English in Ghana and Kenya; French in Senegal and Madagascar; and Portuguese in Angola and Mozambique. Typically, European languages are given official status in the former colonial realm for two reasons: The country contains numerous ethnic groups, some of which have a history of friction. Elevating one local language to official status could lead to jealousy and unrest on the part of other groups. Use of a European tongue favors no one and, in effect, puts everybody at an equal disadvantage. Use of a European tongue stands to promote international trade and commerce more than would a local language, which may be spoken nowhere else on Earth. Nevertheless, many (even most, in some cases) of the native peoples in these countries continue to speak their own tongue as the vernacular language. In most cases, use of the official language(s) is concentrated in the cities and larger towns, while the vernacular persists in the smaller towns, villages, and rural areas. To the extent that everyday use of the official language is gradually "trickling down" from urban to rural areas, its spread exemplifies the process of hierarchical diffusion. Checking the physical effects Language and physical geography may interact in various ways. The two most significant ways are through environmental terminology and linguistic refuges. Environmental terminology Languages tend to develop robust vocabularies that pertain to locally observed environmental conditions, and weak vocabularies that pertain to unfamiliar settings. English, for example, is weak in native terminology that pertains to deserts, the sub-arctic, very mountainous areas, and other characteristics that are not common to England. Thus, English has adopted environmental terminology from other languages to describe things that English cannot, or at least not very well. Accordingly, standard English dictionaries now include terms such as arroyo (from Spanish) to describe intermittent streams in desert environments, taiga (from Russian) to describe high-latitude coniferous forest, and fiord (from Norway) to describe steep-sided, glacially carved inlets of the sea. Linguistic refuges A linguistic refuge is an area where a language is insulated against outside change by virtue of remoteness, or the remains of a locale where a once widespread language continues to be spoken. Acting as physical barriers, aspects of the physical environment have served to isolate speakers of various languages and thus preserve their native tongues from outside agents of change. Heavily forested and extremely mountainous areas have historically served that purpose. The traditional Welsh and Irish languages, for example, at one time appeared to be on the brink of extinction, relegated to remote peninsulas, islands, and valleys in their homelands following the onslaught of English. However, nationalist aspirations and heritage awareness have led to campaigns to resuscitate these languages and promote their everyday use. Central to these efforts have been human resources — native language speakers — many of whom hail from villages and farms in linguistic refuge areas. Playing the landscape naming game Language may provide cultural character to the physical environment as well as to people. For example, what do New Jersey, Lake Okeechobee, Baton Rouge, and El Paso have in common? The answer is they are all toponyms orplace names. People the world over have a habit of naming landscape features, be they mountains, hills, rivers, lakes, bays, seas, deserts, forests, cities, towns, streets . . . the list goes on and on. Toponymy, the study of place names, may provide diverse geographical insights. As per the four locales mentioned, toponyms may tell us something about where the settlers came from, who used to live here, and what language the settlers spoke. Toponyms may also tell us something about past religious distributions. Catholic settlers in North America, for example, had a propensity to bestow religious names on their settlements more so than Protestants, no doubt in part to solicit the protective favor of the Almighty in an often-difficult frontier setting. Thus, towns named for saints abound, especially in Quebec and California (San Diego, Santa Barbara, San Jose, San Francisco, and so on). Place names may also provide philosophical insights. For example, about two centuries ago American culture was affected by the Classic Revival, which involved a new reverence of ancient Greece and Rome. One manifestation is the existence in Upstate New York of literally dozens of cities and towns that were named or renamed in accordance with the classical theme. Examples include Syracuse, Rome, Utica, Ithaca, and Romulus. One of the most maddening things about toponyms is that they can be literally changed overnight, immediately rendering millions of maps and atlases out-of-date. The change of Burma to Myanmar and Zaire to Congo are fairly recent examples. Prior to its dissolution, the USSR contained an estimated 20,000 places named for Stalin — mountains, cities, alleys, you name it (literally). When Stalin's legacy suddenly fell out of favor, so did toponyms in his honor. Few remain.

Article / Updated 03-26-2016

People are fascinated by the world in which they live. They want to know what it's like and why it is the way it is. Most importantly, they want to understand their place in it. Geography satisfies this curiosity and provides practical knowledge and skills that people find useful in their personal and professional lives. This is nothing new. From ancient roots . . . Geography comes from two ancient Greek words: ge, meaning "the Earth," and graphe, meaning "to describe." So, when the ancient Greeks practiced geography, they described the Earth. Stated less literally, they noted the location of things, recorded the characteristics of areas near and far, and used that information in matters of trade, commerce, communication, and administration. Disputed paternity A Greek named Eratosthenes (died about 192 B.C.) is sometimes called the "Father of Geography" because he coined the word geography. The Greeks themselves called Homer the "Father of Geography" because his epic poem, The Odyssey, written about a thousand years before Eratosthenes was born, is the oldest account of the fringe of the Greek world. In addition to these gentlemen, at least two other men have been named "Father of Geography," all of which suggests a very interesting paternity suit. That the story goes back to the days of the Greeks tells you that geography is a very old subject. People of every age and culture have sought to know and understand their immediate surroundings and the world beyond. They stood at the edges of seas and imagined distant shores. They wondered what lies on the other side of a mountain or beyond the horizon. Ultimately, of course, they acted upon those speculations. They explored. They left old lands and occupied new lands. And as a result, millennia later, explorers like Columbus and Magellan found humans almost everywhere they went. Links to exploration Geographers from ancient Greece through the nineteenth century were largely devoted to exploring the world, gathering information about newfound lands, and indicating their locations as accurately as possible on maps. Sometimes the great explorers and thinkers got it right, and sometimes they did not. But in any event, geography and exploration became intertwined; so, "doing geography" became closely associated with making maps, studying maps, and memorizing the locations of things. . . . To modern discipline During the past century, and especially during the past several decades, geography has blossomed and diversified. Old approaches that focused on location and description have been complemented by new approaches that emphasize analysis, explanation, and significance. On top of that, satellites, computers, and other technologies now allow geographers to record and analyze information about the Earth to an extent and degree of sophistication that were unimaginable just a few years ago. As a result, modern geographers are into all kinds of stuff. Some specialize in patterns of climate and climate change. Others investigate the distribution of diseases, or the location of health care facilities. Still others specialize in urban and regional planning, or resource conservation, or issues of social justice, or patterns of crime, or optimal locations for businesses. . . . The list goes on and on. Certainly, the ancient ge and graphe still apply, but geography is much more than it used to be.

Article / Updated 03-26-2016

The oceans have warm and cold surface currents that act like a global heating and air-conditioning system. They bring significant warmth to high latitude areas that would otherwise be much cooler, and significant coolness to low latitude areas that would otherwise be much warmer. The currents also play a major role in determining the global geography of precipitation. The sun can more easily evaporate warm water than cold water, and thereby produce the atmospheric vapor that results in rain. Therefore, lands that get sideswiped or impacted by warm currents tend to have abundant precipitation in addition to a comparatively warm climate. Conversely, lands impacted by cold currents tend to receive very little precipitation in addition to a comparatively cool climate. Generally, surface currents exhibit circular movements (see Figure 1). North of the equator, the flow is usually clockwise. South of the equator, the flow tends to be counter-clockwise. These movements are principally products of prevailing winds that "push" the ocean's surface. On the map you can see occasional exceptions to the general rules of circulation. They are the results of deflections caused by the angle at which a current strikes a land mass or the continental shelf, or by the direction of prevailing sea level winds at particular latitudes. Figure 1: A generalized geography of ocean surface currents. Warm currents, cold currents The warm and cold portions of these circulatory systems have rather predictable geographies. As ocean currents move westward along the equator, they absorb lots of solar energy, heat up, and become warm currents. As they turn away from the equator, they generally continue to absorb about as much heat as they dissipate, at least while they remain in the Tropics — that is, the region between the Tropic of Cancer and the Tropic of Capricorn. After leaving the Tropics, the reverse starts to happen: The currents radiate more heat than they gain — but slowly. Thus, the currents remain comparatively warm longer after they have left the tropics. The Gulf Stream, for example, is a warm-water current that moves up the Eastern coast of the United States and then becomes the North Atlantic Current (see Figure 1). Although it loses a fair amount of heat as it moves eastward across the mid-Atlantic, the North Atlantic Current reaches Europe with a considerable amount of stored heat remaining. As it continues to radiate that heat, it contributes to the climate of Northwestern Europe a degree of warmth that is unusual for those latitudes, and also abundant rainfall. Going against the norm: El Niño and La Niña You should remember that climate is an average of yearly conditions, but that in any given year very "un-average-like" events can occur. El Niño and La Niña, which happen every so many years, provide good examples. (Niño and niña mean boy and girl in Spanish.) As you can see in the bottom part of Figure 2, during an El Niño, the surface waters become unusually warm in the tropical portion of the Pacific. The reasons for this aren't fully understood; but because the conditions occur around Christmas in the waters off western South America, the local populace call it El Niño, referring to the Christ child. During La Niña, the opposite happens ("girl" being the opposite of "boy") — the water is unusually cold. Figure 2: Conditions associated with La Niña (top) and El Niño (bottom). The affected ocean water circulates and also influences the behavior of atmospheric pressure belts, and the impact can be substantial and widespread. Just what that means varies from place to place and year to year. Sometimes, for example, rainy seasons become extremely stormy and dry seasons become prolonged droughts. On the other hand, the effects are not always bad, as may be evidenced perhaps by a normally harsh winter that turns up mild. Generally, the media have cast "the boy" and "the girl" as climatological brats. In some times and places, however, they are the most pleasant kids you'd ever want to have around.