Welcome to the first part of a new series. In this series I want to explore the concept of a
pole shift and what the evidence for or against it. Charles Hapgood has probably done the most
in terms of defining the evidence in support of this model but how well does this stack up
against more up to date information? In this part, we will explore our failure to explain ice ages
and question if this supports an idea of a shifting pole?
We need only go back 100 years to find people were astonished at the suggestion that great ice sheets
over a mile thick covered the temperate lands of North America and Europe. Many attempted to
discredit the idea but eventually, people accepted the idea of not one but a series of ices ages.
As more discoveries were made it became evident that these ice ages happened on all continents,
even in the tropics, such as tropical India and equatorial Africa.
Many theories were put forward as to the cause of the ice ages. In 1929 Coleman
was one of the leading authorities on ice ages wrote the following:
Scores of methods of accounting for ice ages have been proposed,
and probably no other geological problem has been so seriously discussed,
not only by glaciologists, but by meteorologists and biologists;
yet no theory is generally accepted. The opinions of those who have written on the subject
are hopelessly in contradiction with one another, and good authorities are arrays on opposite sides
25 years after this both Umbgrove and Daly agreed that the situation
described by Coleman was essentially unchanged.
Even today this remains true. Ice ages are generally described as a long period
of a reduction in the temperature of Earth’s surface and atmosphere,
resulting in the presence or expansion of continental and polar ice sheets and alpine
glaciers. It is believed that the earth goes through periods of ice ages followed by greenhouse
periods during which there are no glaciers on the planet. The exact cause of ices ages is still not
fully understood for either the large scale ice age periods or the smaller ebb and flows.
Misplaced Ice caps
One of the problems that has been difficult to explain is the location
of the great ice caps of the past. These ice caps have refused to have
anything to do with the polar areas of the present day.
The original idea was that during a glaciation period the ice caps would fan
out from the poles. The problem was that some northern countries were never covered in ice
and that in reality there were several more or less distinct ice sheets starting from local
centres, and expanding in all directions. As an example Siberia, Alaska and the Yukon territory,
now some of the coldest places on Earth were free of ice at one stage while at the same time
northern Europe, with its mild climate, was buried under ice as far south as London and Berlin.
This is probably one of the most compelling pieces of evidence of
a pole that appears not to be located at our current pole.
What about the older ice ages do they show evidence of misplaced ice caps?
At the time that Hapgood wrote his book, the Permo-Carboniferous ice sheet
was one that would on first examination provided evidence of a pole that had shifted. Here they
had identified that an ice sheet existed in southern India, Africa and Australia.
Hapgood examined the Indian ice sheet and saw that it moved northwards but generally,
ice sheets flow from a central point, where the ice is thicker, and move out in all directions.
This would mean that the Indian ice sheet must have extended to the equator. This turned out to
actually be a key piece of evidence in support of the idea that the continents had moved. As further
analysis of the movements of the ice sheets revealed that they all appeared to be moving away
from a central point in Antarctica. This meant that they must have been much closer together.
Worldwide Phases of Cold Weather
A widely accepted assumption to explain ice ages is that they occurred as a result of a lowering
of the average temperature of the whole surface of the earth at the same time. This has lead many
geologists to look for explanations for ice ages only in mechanisms that affect the whole planet.
Causing a simultaneous effect in both the northern and southern hemispheres.
It is truly a remarkable failure that this assumption has been maintained over such a
long period of time despite the fact that it is in sharp conflict with the basic principles of
physics in the field of meteorology. Put simply glacial periods were periods of heavier rainfall
in areas outside the regions of the ice sheets, so together with the deep accumulations of ice
in the great ice sheets, must have involved a higher average rate of precipitation
during ice ages. There is a great deal of geological evidence to support this.
Great pluvial periods in Africa during the Pleistocene era seem to support this
idea. If precipitation is to increase this also means a greater supply of moisture in the air.
The only possible way to increase the amount of moisture in the air is to raise the temperature
of the air. If rainfall was much higher in certain areas during an ice age this
would also require over large areas much greater evaporation and also require a warmer climate.
This is in direct conflict with the idea of lower average temperatures across the entire globe.
Moreover, the weakness of geological evidence also seems to undermine the
assumption of a whole planet effect. Kroeber had the following to say
There is plenty of geological evidence, in many parts of the earth,
of changes of climate, especially between wet and dry areas;
and some of these happened in the Pleistocene. But the correlation of such changes as they occurred
in widely separated regions, and especially as between permanently ice-free and glaciated areas,
is an intricate, tricky, and highly technical matter, on which the anthropological student must
take the work of geologists and climatologists, and these are by no means in agreement.
They may be reasonably sure of one series of climatic successions in one region, and of
another in a second or third region; but there may be little direct evidence on the correspondence
of the several series of regions stages, the identification of which remains speculative.
Kroeber’s statements were made before carbon dating dramatically shortened the duration
of the last North American ice age from about 150,000 years to about 50,000 years. If we are
to assume that the same mechanism must equally have caused ancient glaciations, of which we know
little, then we must also consider the possibility that these too may have been of short duration.
If this is true how is it possible to establish the fact that they were contemporary in both
hemispheres? A geological period has a duration of millions of years. An ice age in Europe and one in
Australia might both be, for example, of Eocene age, but the Eocene Epoch is estimated to have
lasted 15 million years. We can discriminate roughly between strata dating from the early,
middle, or late Eocene, but we have no way of pinpointing the date of any event in the Eocene.
Even assuming the use of Radiometric dating it is not possible to date rocks within a margin of
error of about 1 million years. It is therefore not possible to determine that an ice sheet
in one hemisphere was really contemporary with an ice sheet or an ice age in the other.
So what are the current ideas on the causes of ice ages?
It is now thought that no single factor was important but that it was a combination of
factors. Some of these have changed since the time Hapgood conducted his research but some have not.
Changes in the Earth’s Atmosphere: The idea here is that a global fall in
CO2 levels would trigger a global cooling. These changes in CO2 levels at the end of an ice age
are thought to be related to increased volcanism.
Position of the continents: Here the explanation is that if
the continents are in positions that block or reduce the flow of warm water from the equator
to the poles and therefore allowed ice sheets to form. The ice sheets increase Earth’s reflectivity
and therefore also reduce the absorption of solar radiation. This creates a feedback loop. What
is not really clear is what then breaks this cycle to suddenly stop this run away system?
Fluctuations in Ocean Currents This is similar to the last one
Variations in Earth’s orbit The Milankovitch cycles are a set of cyclic
variations in characteristics of Earth’s orbit around the Sun. Each cycle has a different length,
so at times their effects reinforce each and at other times they cancel each other out.
The problem is that this explanation struggles to explain the dominance
of the 100,000 year cycle over the last 8 cycles.
5 Variations in the Sun’s Energy output
There are at least 2 types of variations in the Sun’s energy output:
In the very long term, they believe that the Sun’s output
increases by about 7% every one billion years Shorter term variations such as sunspot cycles,
and longer cycles such as Solar Minimum and Maximum
And lastly Volcanism Both in terms of dust
particles causing a cooling and also increased CO2 causing a heating effect.
The problem is that neither one of these alone is capable of explaining the repeated ice ages
and that is why they have to invoke that it must be a combination of factors.
The problem of timescale
As we have discussed earlier geologists are likely to consider a million years
as almost nothing. Events that took place within a 20 million year event
would be considered to be part of the same event.
As for the ice ages, the older ones were simply thrown into one of these long geological periods
when in reality there was no way of determining their duration, speeds of development, or exactly
when they occurred. It was easier to assume that they had endured for millions of years.
When we examine the most recent division of geological time, the Pleistocene, geologists had
much more evidence to work with and saw that there were 4 ice ages in a period of about 1 million
years. They, therefore, proposed the idea that the Pleistocene was not like any other time period
that came before it. The was due to there being so many ice ages but it must be realised that
evidence for ice ages can quickly be destroyed and therefore as we look further back in time
the likelihood of finding this decreases and would make the record appear more smeared out.
As an example, the last ice was initially considered to have begun 150,000 years ago and
ended 30,000 years ago. This was based on strong evidence. Any expert who claimed that the ice age
must have been more recent was laughed at. Even when data appeared that seemed to show the ice
sheets had not receded until as recently as 13,000 years it was ignored for a further 30 years.
It wasn’t until after the second world war that radiometric dating
was able to show that many of the ice sheets had not retreated until much later.
This now meant the ice sheets had retreated in a timeframe that geologists were simply
not used to dealing with and this contradicted some basic assumptions of geological science.
What had become of those gradually acting forces that were supposed to govern glaciation as
well as geological processes? What factor could account for such an astonishing rate of change?
The next bombshell to hit geologists was that this most recent ice age had not started 150,000 years
ago and continued until only 13,000 years ago. New dating techniques showed that this ice sheet
was only 25,000 years old. Meaning that this ice age had only lasted 15 to 20,000 years. At first,
they tried to blame the reliability of the dating method to evade the problem.
It appeared that the Wisconsin ice cap went through a number of oscillations,
warm periods of ice recession alternating with cold periods of ice re-advance.
The exact mechanism that causes this rapid change is unclear.
So although the exact mechanism of an ice age is still open to debate does any of this actually
point to a shifting of the poles? It is much harder to establish this based on the older data
as this tends to largely show that the contents were not located where they are today
and when it is thought all the continents formed a supercontinent. Any shift of the crust would
therefore not be easily seen but there may still be some discrepancies that are worth
discussing in the next part. The more recent data does tend to point to something causing
a change in the location of the pole in order to allow certain northern parts to remain ice-free.
In the next part, we will examine the climate record and plant and animal find,
and also look at the paleomagnetic record which does in some cases show a sudden shift of the pole
despite the movement of the continents.