Tag Archives: Oxygen

Astronomy, Cycles and Climate Change

Facebooktwitterlinkedininstagram

Cycle: ( noun) A series of events that are regularly repeated in the same order (Oxford Dictionary)

 

milankovitch conglomerate cycles

Natural cycles are all around us; tides, seasons, sun spots, birthdays, El Niño.  In geology we can identify cycles at many different scales, from the really grand to the wafer-thin (deference to Monty Python), from those that span eons, to cycles that repeat every few seconds.  Perhaps the grandest of earth cycles are those that last 100-300 million years and involve the formation and destruction of tectonic plates.  On a more human time scale there is the seemingly never-ending train of waves rushing to meet you on your favourite beach. Continue reading

Facebooktwitterredditlinkedin
Facebooktwitterlinkedininstagram

The Bubbles That Changed our Perspective on the World’s Climate

Facebooktwitterlinkedininstagram

ice - water supply

One of my geology field seasons in the Canadian Arctic worked out of a base-camp on Axel Heiberg Island (west of and snuggled against Ellesmere Island).  It was the spring thaw and all rivers and streams were muddy.  Our only source of clean water turned out to be a small melt-water pond atop an iceberg in Strand Fiord, a few hundred metres offshore.  The helicopter would make daily trips with a 45-gallon drum to collect the water.  The ice and its water were crystal clear and probably a few thousand years old. It was a treat. Perhaps the only thing missing was the occasional Scotch or G&T. Continue reading

Facebooktwitterredditlinkedin
Facebooktwitterlinkedininstagram

The Ancient Earth: 4. Water – Oceans of the stuff

Facebooktwitterlinkedininstagram

The Ancient Earth 4.  Where did all that water come from?

2013-10-14 Kantan4 stormThe oceans cover 71% of our planet, and account for 97% of its total surface water.  The greatest ocean depth is 10,994m in the Mariana Trench (near the Island of Guam), and the shallowest …, well most of you have been to the beach.   They harbour a massive biomass (micro and macro) that comprises beautiful and complex ecosystems; they help feed our burgeoning population.  They provide opportunities for explorers and metaphors for poets.  But where did all that water come from? Continue reading

Facebooktwitterredditlinkedin
Facebooktwitterlinkedininstagram

Ancient earth. 3 The air we breath; how our atmosphere evolved

Facebooktwitterlinkedininstagram

land sea air

The really ancient earth: How our atmosphere evolved

Take a deep breath. Savour it.  One of the few absolutes of our physical world (that we probably haven’t looked after as well as we might have).  This post continues the theme “The Really Ancient Earth” by looking at what we know about the origin of our atmosphere; some of the evidence and some of the hypotheses.  What was it like on day 1 (about 4600 million years ago) and how did it evolved into our breath-taking world today? Continue reading

Facebooktwitterredditlinkedin
Facebooktwitterlinkedininstagram

Ancient earth. 1 A time-line for the first 4 billion years

Facebooktwitterlinkedininstagram

A time-line for the first 4 billion years of Earth history

The Cambrian, that relatively brief period in geological history (40 odd million years) was witness to one of the most amazing series of biological events in the entire history of the Earth; the rapid, almost explosive appearance of marine critters with preservable shells and skeletons – a real first.  Trilobites are probably the best known fossils from that period, but there are also some pretty weird and wonderful looking soft-bodied creatures (one famous fossil locality is the Burgess Shale near the town of Field, British Columbia).  Most animal life today can track its origin to those early life forms.  These events began about 540 million years ago (how easy these numbers roll off the tongue, or pen).  But we also know that our Earth is pretty close to 4600 million years old (4.6 billion – How old is Earth); in other words there is almost 4 billion years, a humongous period of time in which, seemingly, not much happened.  4000 million years worth of boredom!  This period is know as the “Pre” Cambrian, or Precambrian.  Most Precambrian events did take place pretty slowly, but these events also determined the kind of world we now live in: the air we breath, the oceans and rivers, the biosphere and indeed life itself, all originated and evolved over this, the deepest of geological time. Continue reading

Facebooktwitterredditlinkedin
Facebooktwitterlinkedininstagram