colony of rats on the surface and almost certainly numerous complaints to the control agency. In short, the uncontrolled populations of rats in sewers constitute a reservoir which extends into all parts of a city and is capable of establishing new infestations on the surface. The structural damage caused by sewer rats can be considerable. They are
The Saffir-Simpson scale measures the intensity of a hurricane. Wind speed is measured on a scale of 1-5 to give an estimate of potential property damage and flooding along the coast. The Categories are as follows: Category One Hurricane: Winds 74-95 mph.
The aftermath of an earthquake, Golcuk, Western Turkey. The power of an earthquake is measured using a seismometer. A seismometer detects the vibrations caused by an earthquake. It plots these vibrations on a seismograph. The strength, or magnitude, of an earthquake is measured using the Richter scale. The Richter scale is numbered 0-10. 1  Earthquakes measuring just one or two on the scale are very common and can happen everyday in places like San Francisco. 2  These earthquakes are so small that people cannot feel them, they can only be picked up by a seismometer.