Skip to content
Advertisements

Stevns Klint

March 24, 2013

stevns klint    stevns klint3     stevns_klint_oversigt

Gifts from the cliffs

Thirty miles south of Copenhagen a dark layer runs through the chalk sea cliffs. It dates to about 66 million years ago and occurs in sedimentary rocks of that age all over the world. Stevns Klint is one of the best exposures in Europe. Below it dinosaur fossils are abundant, above it they’re absent, and many years above mammal fossils appear. The layer itself contains high levels of iridium, an element rare on earth but common in asteroids.

You’ve guessed. This is the c[K]retaceous-tertiary (K-T) boundary, caused by an asteroid hit on the coast of Mexico; global winter, mass extinction and the Chicxulub crater the result.

Hojerup, with car park, museum and an excellent restaurant, a bit south of the red arrow on the map above, is the best access spot.  Descend the steps by the old church on the cliff edge; legend says it never falls into the sea despite the eroding cliffs, because every night, when no-one’s looking, it hops inland a bit!  A few yards south along the shingle, scramble up to see and touch the boundary layer.  So many people have done so that there is a large overhang, so don’t stay long. Have a swim instead.

I’ve been twice, and collected quite a few bits of the boundary layer. I often award visiting speakers to our department with a piece, but I rarely get round to adding a note to remind them why their gift of crumbly grey rock is interesting. Now I can print off this post.

Jim Thornton

Advertisements
One Comment leave one →
  1. Myles permalink
    March 7, 2014 4:43 pm

    A great post about a boundary layer.
    Theres also a boundry layer called the “snowline” above which its freezing. Literally below zero degrees. Which brings me to……

    IS GLACIAL RETREAT ANOMALOUS. ?

    THE SCARE STORY is that global warming from Co2 is going to melt the glaciers of the world causing widespread ecological disasters. That in fact they will continue to melt at an increasing rate and eventually vanish. For example in the paper “Climate Change in Relation to the Himalayas-S.P.Singh.” he says…

    “…rivers and adjoining grassland and forest ecosystems would be severely affected by the phase of rapid snow melt and subsequent phase of the absence of the snow melt water forever with the loss of glaciers.”

    THE TRUTH is that glaciers will never melt back above the SNOWLINE due to that being the height at which atmospheric temperature becomes ZERO.

    This line varies but as a rule of thumb a glacier forms above the snowline and then advances down into above zero temperatures, the region where it can actually melt. How much could global warming allegedly from Co2 push this line up.? The answer is a negligible amount. Therefore there will be no “loss of glaciers” as alleged by climate science.

    THE ASSUMPTION is that glacial retreat is unusual, unprecedented and occurring at a rate faster than has ever been seen before because of AGW. Research into the history of glaciers reveals a different picture. Glaciers have been advancing and retreating constantly for thousands of years. The most recent peak in length of glaciers being with the peak of the little ice age. A short 3 page paper here to verify this: http://www.episodes.co.in/www/backissues/101/ARTICLES–26.pdf

    Naturally after reaching a MAXIMUM size with the peak of the Little Ice Age the glaciers started retreating. The glacial retreat of some areas started well before AGW was an issue and has carried on to the present day. Just as the planet has warmed up since the unusually cold little ice age so the glaciers retreat as well. So really the question is what length should they be melting back to. ? What is the normal size of a glacier. ? What length were the glaciers before the little ice age.?

    Well the paper points out that there have been many phases of growth and retraction in the past few thousand years prior to which the glaciers were more “recessed”. That means the natural or normal length of a glacier is somewhere between “recessed and maximum extension”. There is nothing unusual about glaciers worldwide melting back. The melt wasn’t started by mankinds Co2 so any modern warming can only be a negligible contributor to the natural process not the cause plus the melt can only max out at the snowline after which the build up of snow and ice will start the next advance. No crisis, no anomalies, just normal “Holocene Glacier Fluctuations”. ( Myles.)

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: