In geology what does ka stand for

That makes it difficult to appreciate the extent of geological time. To create some context, the Phanerozoic Eon the last million years is named for the time during which visible phaneros life zoi is present in the geological record.

Mammals have dominated since the demise of the dinosaurs around 65 Ma, or 1. Geologists and geology students need to understand geological time. For example, the Atlantic Ocean between Nova Scotia and northwestern Africa has been getting wider at a rate of about 2. Imagine yourself taking a journey at that rate — it would be impossibly and ridiculously slow.

A useful mechanism for understanding geological time is to scale it all down into one year. The origin of the solar system and Earth at 4.

At this scale, each day of the year represents If this were a legal dispute, Christie-Blick would be arguing that the year has no standing. Actively scan device characteristics for identification.

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Ages are abbreviated from Latin: Ga giga-annum is a billion years, Ma mega-annum is a million years, ka kilo-annum is a thousand years. Duration, on the other hand, has been abbreviated from "years. There's a move to use the same abbreviations for both: Ga, Ma, ka, etc.

The main argument for using Ma to represent durations is that geologists are used to thinking about numbers meaning ages: 70 Ma refers to a time in the Cretaceous. My take: I don't have a strong opinion. It takes practice to make the distinction, and my students tend to ask why we need two units, and I don't really have a problem telling ages from lengths of time.

I can usually handle subtraction, though it's more difficult when I'm dehydrated at the end of a long day in the field. Pretty much everything is more difficult when I'm dehydrated. But I'm willing to be convinced. So what do you think? If you've got a really strong opinion, GSA is taking comments. But I'm happy to listen if you want to lay out your favorite argument here, too. That seconds comment is not funny- just try calculating ages with second-based decay constants and everything else in years and see what happens As for the subject, if we were to adopt the IBBQWTF suggestion, and use Ma for everything, future geologists would get really confused when reading current papers, unless they were specifically told that Ma used to mean something else.

Speaking of physicists, for your amusement, I'll mention that they are talking about logarithmic time. The ordinary second is not fundamental in any physics sense. Fundamental would be the Planck time about 1e seconds.