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A megaannus (Ma) represents one million (10 6) years. The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth.
Yet, compared to such human-made objects, the vastness of geological time—which is measured by millions and billions of years, and referred to by essayist John McPhee as “deep time”—is truly staggering, a view captured eloquently in a recent essay in the New York Times by Peter Brannen.
• Scale: 1 inch = 100,000,000 years • 4.6 billion years = 46 inches • E.g. Mr. Inman’s mother was born 1,625,000,000 years ago. Where would this be on the time line?
On the back of this sheet is a chart showing the geologic eras, systems, and series; the oldest is at the bottom. On the chart, each dot, number, or letter represents 1 million years. The dots get “older” as you read down the chart, or to the right along a row.
Constantly writing out millions and billions of years is time-consuming, so when geologists talk about ages, they use a few abbreviations. The symbols ka (thousands), Ma (millions), and Ga (billions) refer to points in time like a date. For example, the dinosaur extinction occurred at 66 Ma.
22 Μαΐ 2008 · opposed to a “billion” years. Students have a hard time believing that if the field represents 4.5 billion years, then a million years would be represented by approximately 2 centimeters (0.8 inches). This can sometimes move them from thinking a million years is impossibly long (“never
At that rate, each hour of the year is equivalent to approximately 500,000 years, and each day is equivalent to 12.5 million years. If all of geological time is compressed down to a single year, Earth formed on January 1, and the first life forms evolved in late March (~3,500 Ma).
