Geography Reference
In-Depth Information
Wind
In innumerable instances, smoke and pollutants from a manufacturing or electrical generating plant
go up a chimney (point source) and end up in the atmosphere. Here, too, the resulting environmental
impact would be nominal if nature just stayed put. But, of course, it does not. Wind is another com-
ponent of the dynamic environment. In Chapter 9, I discussed how solar energy leads to creation of
high- and low-pressure systems that cause wind. And as a result, pollution that starts out as a very
localized phenomenon becomes geographically general.
For example, as sanitary landfills fill up, incineration is increasingly looked to as a means of solving
garbage disposal problems, especially in big cities. But even the most efficient incinerators generate
pollution that is released to the atmosphere, and then spread over wide areas, thanks to wind. Thus, a
source of point pollution (the incinerator chimney) may affect the health of humans, vegetation, and
property values over a wide area.
Currents
In many times and places, oceans have been convenient receptacles for human refuse. Also, as the
global economy has grown and become more inter-connected, maritime traffic has increased, and
with it the possibility of incidents that result in the release of cargo that is harmful to the environment.
At this point the familiar story line repeats: If nature stayed put, then the impact would be minimal.
But we live in a dynamic environment. The oceans are restless. Surface currents (see Chapter 9) can
carry things far and wide while tides and waves can affect every coastal nook and cranny. Once again,
therefore, nature can spread the mess, so what starts out as a local event is turned into an issue of
greater geographical proportions.
The possibilities were amply demonstrated on March 24, 1989, when the Exxon Valdez oil tanker
went aground in Prince William Sound, Alaska, and ultimately spilled about 11 million gallons of
crude oil into the sea (Figure 18-2). Although the Sound is a somewhat confined water body, the
Alaska Current slowly and inexorably began spreading the mess — in this case, the oil slick — in a
westerly direction. Coastline 400 miles away was eventually affected. However, given the numerous
islands and inlets that characterize the region, some 3,000 miles of shore were contaminated. (Dead
wildlife included more than 575,000 birds.)
