Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: Thefruitreeoflife on 12/05/2011 06:14:01

Title: How do humans have an effect on the rock cycle?
Post by: Thefruitreeoflife on 12/05/2011 06:14:01
Give examples and facts to support your answer. [;)]


Lol, I like this [O8)].
Title: How do humans have an effect on the rock cycle?
Post by: Bass on 13/05/2011 04:02:51
Resource extraction, pollution, climate change, excavations etc.

But in all likelihood, our impact is minimal.  40 million years from now it may be hard to find any evidence of our existence.

I guess it all depends on the reference scale.
Title: How do humans have an effect on the rock cycle?
Post by: Ophiolite on 18/05/2011 12:30:26
Give examples and facts to support your answer. [;)]
Homework is fun, isn't it?

Quote from: Bass
But in all likelihood, our impact is minimal.  40 million years from now it may be hard to find any evidence of our existence.
You are overlooking our primary role in initiating and sustaining a mass extinction.
Title: How do humans have an effect on the rock cycle?
Post by: CliffordK on 18/05/2011 20:31:56
If you consider sedimentary rock, then we would have an effect of it.  Especially in River Deltas where we often put in dikes to maintain river channels and use other flood control means, effectively preventing the sediments from being deposited, or displacing the sediment deposits to other areas.

Perhaps in all urban areas, once we lay down a road bed, we start maintaining the elevation with respect to that road bed.

However, also keep in mind that the "rock cycle" is excruciatingly slow.  It may take millions of years to go from sediments deposited at the surface to sedimentary and other forms of rock.

While we may actively mine certain types of rock, we likely have minimal impact on other parts of the rock cycle.  We currently have little control of volcanism.  And, for example Iceland uses significant amounts of geothermal energy, but the region remains very active volcanically. 
Title: How do humans have an effect on the rock cycle?
Post by: imatfaal on 18/05/2011 21:28:01
Indeed - Nature had an news article last week (12 May page 133) about the possibility of defining a new epoch, the Anthropocene.   If you cannot get behind pay wall let me know and ...
Title: How do humans have an effect on the rock cycle?
Post by: CliffordK on 19/05/2011 06:11:52
Indeed - Nature had an news article last week (12 May page 133) about the possibility of defining a new epoch, the Anthropocene.   If you cannot get behind pay wall let me know and ...
There seem to be many comments on the WWW on Anthropocene including a Wikipedia article.

http://en.wikipedia.org/wiki/Anthropocene

Not particularly discussing the formation of rock, but the influence of Man on the environment.  And I suppose future man will be able to find signs of 20th century main in the rock records including Nuclear Fallout from WWII, Nuclear Testing, Chernobyl, and Fukushima.

The question is how do you define Anthropocene, and how is it differentiated from Holocene?

Beginning 12,000 years ago at the beginning of the Holocene?
Beginning 8,000 years ago after an early human population expansion?
Beginning 2,000-3,000 years ago, in the time of Christ, Greeks, Egyptians, etc?
Beginning in 1776 & the American Revolution?
Beginning in 1900, with the automobile, airplane, mass production, etc?
Title: How do humans have an effect on the rock cycle?
Post by: imatfaal on 19/05/2011 10:32:36
Quote
Beginning in 1776 & the American Revolution?
At the risk of being called Eurocentric - that's a bit of an odd choice.  Geologically there isn't much difference between the redcoats and the minutemen. 

The two dates I heard discussed were the industrial revolution and the first use of atomic weapons.  The other ideas discussed were thought to be a little too transitory in geological/historical terms and not sufficiently global - the move to farming, the increase in cities, and the age of capital/mass production.
Title: How do humans have an effect on the rock cycle?
Post by: CliffordK on 19/05/2011 12:55:00
Quote
Beginning in 1776 & the American Revolution?
At the risk of being called Eurocentric - that's a bit of an odd choice.  Geologically there isn't much difference between the redcoats and the minutemen. 

The two dates I heard discussed were the industrial revolution and the first use of atomic weapons.

In most accounts, the Industrial Revolution dates back to somewhere between the mid-1700's to the early 1800's.  So, right around the beginning of the USA as an independent nation would be a major turning point for the industrialization of Europe, as well as the Eastern USA (west would have still been pretty wild at that time). 

It would also have heralded the beginning of the end of the colonial period. 

Atomic Weapons?
I assume that is one "marker" that will be visible in sedimentary layers everywhere.  WWII would have also brought the beginning of the computer revolution.  Not necessarily a geologic step, but certainly a step with extreme socio-economic implications, as well as significant increases in power and energy requirements.
Title: How do humans have an effect on the rock cycle?
Post by: imatfaal on 19/05/2011 14:27:01
Yeah - if you had to put a single date on industrial revolution I would be thinking of the dates of Watts/Boulton Steam engine advances about 1778-1783 - in England we tend to see Iron Bridge in Telford as a still visible tangible starting point. 

I would have to defer to the real rock-kickers on the forum but I agree that markers from the increased industrialization and those from atomic weapons will be visible for many years to come.  Distressingly they will probably still be measurable well AFTER the anthropocene epoch has finished.