The Naked Scientists

The Naked Scientists Forum

Author Topic: Previous Global Warming evidence?  (Read 3420 times)

Offline OokieWonderslug

  • Full Member
  • ***
  • Posts: 93
    • View Profile
Previous Global Warming evidence?
« on: 29/06/2012 13:48:27 »
Ok, studying Google Earth shows that the east coast of the US had a different shoreline not too long ago. It is obvious that the ocean was 250ft higher than it is today. And judging by the lack of erosion in this ancient ocean bed shows it could not have been millions of years ago. Even with low altitudes you still get erosion and there is no relief past the 250ft mark. Further there are the remains of beaches at the 250ft mark.

So here is my theory: Before a new ice age starts ALL of the ice melts everywhere first. It certainly appears to me that the old shoreline is about the age of the start of the last ice age. What we see now is everything melting and blaming it on man. That is just silly. The melt off appears to be a normal part of the cycle.

Now I know some of you will try to claim that the beaches are from millions of years ago, But sand is soft and it erodes easily and there would be more relief if that was the case. Instead you have pretty much perfectly flat sand for 100 miles. The channels for rivers are not very wide. I measured one at 3 miles. That is not far for a river to meander in millions of years, but it is far enough for tens of thousands of years.  Had the sand been buried  and re exposed there would be more relief. There would be "islands" of harder materials that did not erode as fast and there are none.

Furthermore, if the ocean level dropped fast enough that would have left enormous areas of sand exposed to the elements and that would explain the sandhills and other areas of ancient wind blown dunes. But they ain't that ancient. They would have blown off the beaches and former seabed recently.

Ideas? Criticisms? Tell me once more why I am wrong?


 

Offline CliffordK

  • Neilep Level Member
  • ******
  • Posts: 6321
  • Thanked: 3 times
  • Site Moderator
    • View Profile
Re: Previous Global Warming evidence?
« Reply #1 on: 29/06/2012 20:54:51 »
Interesting theory.

Many temperature proxies indicate that the Eemian interglacial peaked at higher temperatures than the Holocene, although it may have had a sharp peak, followed by later levelling off of temperatures.  According to the Wikipedia link, Eemian sea levels peaked at about 20 feet higher than today.

Some Antarctic ice cores cover up to about a half a million years, so at least parts of Antarctica have not melted for quite some time.  Beyond that, I believe much of central Antarctica is melting from the bottom up, rather from the top down, so it may remain with about a half a million years of ice.

As far as the Holocene, I've seen images indicating a gradual sea level rise throughout the Holocene. 
http://en.wikipedia.org/wiki/Current_sea_level_rise


That may, in fact, not be the case.  It is quite possible that in the Holocene, like other interglacial periods that there was an early peak in sea levels followed by a general reduction in sea levels.

http://wattsupwiththat.com/2011/01/05/on-%E2%80%9Ctrap-speed-acc-and-the-snr/


http://www.geo.arizona.edu/palynology/geos462/01histplist.html


So, you may be right that sea levels may have been around 20 feet (3 meters) higher in the early Holocene, merely 10,000 years ago.

If we are in fact causing global temperature changes, the concern is "Climate Change".  Humanity is happy with the current state of the climate, and any uncontrolled change either positive or negative is worrisome.  But, there really is nothing unprecidented with the current changes in temperatures or sea levels.

One corollary to your theory is that if we are in fact raising Earth's temperature, then it could destabilize the Holocene, and eventually cause a rapid drop in temperatures in the distant future.
 

Offline OokieWonderslug

  • Full Member
  • ***
  • Posts: 93
    • View Profile
Re: Previous Global Warming evidence?
« Reply #2 on: 02/07/2012 04:37:51 »
I do not see how there could not be significant erosion of that area in a million years. There would have to be more relief than we see now. You can still see where the shorelines were. They still look like beaches. If/when I ever find a job and have money to travel I will go to one of these shorelines and do some digging and prove they were in fact the beach. Then if only I could find a way to get any organic matter dated when I find it I can be able to say when it was the beach. I am sure others have already done this, but scientists uncooly force folks to pay for their research even though they were already paid to do it. You can't get any information online about past expeditions other than an abstract that tells one nothing.
 

Offline CliffordK

  • Neilep Level Member
  • ******
  • Posts: 6321
  • Thanked: 3 times
  • Site Moderator
    • View Profile
Re: Previous Global Warming evidence?
« Reply #3 on: 04/07/2012 20:34:59 »
It is not the scientists that sell the journal articles, but rather the journals that sell the journal articles.  While a blog or forum is cheap to maintain, a journal article does take an amount of reviewing, editing, and compilation that must be paid for.  Some universities will distribute copies of their published journal articles for free which you may be able to snag with a search for specific authors and titles. 

You can often find the journal articles you are seeking at your local university research library.  And, the libraries pay thousands of dollars a year for each journal subscription.  If the journals were distributed for free to he public, it would be hard to convince the universities of the need to pay for the subscription.  However, over time the world will catch up with the cheap E-Publishing with a wide audience vs the expensive hardcopy publishing & distribution with a limited audience.  But it will take time for that to become mainstream.  As it is, E-Books are often the same price as hardcopy books.

As far as remote beaches.  At least here in Oregon, in some places we have dunes that extend inland for a mile or so.  But they are very dynamic, wind blown structures.  At least they were until the introduction of European Beach Grass a century ago.  While some beach sand may be generated with local erosion, much of it is formed from silt carried downstream in the rivers.  I don't think it would be easy to date a dune.  Certainly elevation is not necessarily representative of the sea level when it was deposited as wind will effectively move and pile up the sand.  Dating a dune would be difficult, although one might be able to date some of the inland islands of organic growth.  The further inland, the trees on the dunes become more established.  But perhaps this is a sign more of stability rather than sea levels rising and falling.

In some places, shorelines are either uplifted or fall with seismic activity. 

Anyway, while you may be able to date some sedimentary layers on a cliff face, going to the beach and digging up some 10,000 year old organic matter and having it carbon dated is not as easy of a process as you might think.

A good picture of previous sea levels may require a global perspective as there may be local phenomena that would obscure the results.
 

Offline OokieWonderslug

  • Full Member
  • ***
  • Posts: 93
    • View Profile
Re: Previous Global Warming evidence?
« Reply #4 on: 04/07/2012 23:46:40 »
I would not try to have a sand dune dated. I was talking beach. There are always organic things washing up on the beach and getting buried. The area I was talking about (near Hartsville, SC) was obviously a beach. The land slowly rises to 250ft ASL and at that level you can easily see where the beach was. The land immediately after the 250ft mark becomes uneven and there are hills and valleys and lots of relief. The land below the 250ft mark is flat and slightly undulating like you would have on the sea floor. I know the sand past that level is wind blown dunes. The sand keeps going for nearly 100  miles in some areas. But it just seems much more likely that those dunes formed when the ocean drained away and there was a 200 or so miles of bare sea bottom exposed.
 

Offline CliffordK

  • Neilep Level Member
  • ******
  • Posts: 6321
  • Thanked: 3 times
  • Site Moderator
    • View Profile
Re: Previous Global Warming evidence?
« Reply #5 on: 05/07/2012 08:14:20 »
I must admit that when looking at lava (& ash), there is a definite difference between the lava and ash deposits that are less than 6000 years old, and those that are greater than 10,000 years old.

I presume the same would be with the sand.  So, if you look at dunes or a beach, it should be apparent if the dunes were laid down in the last 10,000 years, or if they were laid down over 100,000 years ago during the Eamian.

There are not supposed to be any major tectonic plate boundaries along the East coast of the USA, but is it possible that some uplifting events have occurred?
 

Offline OokieWonderslug

  • Full Member
  • ***
  • Posts: 93
    • View Profile
Re: Previous Global Warming evidence?
« Reply #6 on: 05/07/2012 17:32:57 »
There have been a couple uplifts on the East coast "recently". For one, taking into account the current rate of erosion in the Appalachians you would find going back in time that when they were new they would have been impossibly high. Something like twice the height of the Himalayas. That has had researchers to believe that there was a second uplift of those mountains some 20 million years ago. Also you have the Uwharrie mountains. There are studies that claim they were uplifted only 5 million years ago.

But then, the Uwharries make absolutely no sense anyway. There is a sign on the top of Morrow mountain that now says the rhyolite there never erupted to the surface. That seems silly on the face of it since ryholite forms from quick cooling in the air. Plus there is volcanic breccia found there and how in the world do you get breccia without an eruption to the surface?! Also, the rocks here are tuff and argilite that has tiny grains of pumice in them. There HAD to be an erupting volcano somewhere in NC at some point to form these rocks. And since no one has found where the volcano was there is no reason to think it was not Morrow mountain. Logic insists that there has to be a volcanic pipe somewhere in NC. There should be a large feature in the landscape since basalt erodes much more slowly than the rocks of the Carolina slate belt. But it is not there. The ONLY place where it is possible there was a volcano is the Uwharries. Yet they changed the sign to say there never was one. The tuff and pumice got here somehow. Where else could it have come from? There is also a kimberlite pipe somewhere in NC because diamonds have been found here. But since the state is covered in vegetation there is little chance of finding something that small in such a large area.
 

The Naked Scientists Forum

Re: Previous Global Warming evidence?
« Reply #6 on: 05/07/2012 17:32:57 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums