We commonly differentiate the solid earth in terms of its architecture, whether it is the foundations of great mountain ranges, or the solidified magmas that underpinned ancient volcanoes. All rocks, whether layered sedimentary rocks or massive intrusive granites, have unique characteristics that define their physical, chemical and biological make up – their architecture.
WE can also think of groundwater in terms of its own architecture. The productivity of an aquifer depends first and foremost on its porosity and permeability. We can use these two fundamental properties to define the architecture of earth materials.
Mark Twain wasn’t far wrong with this sardonic, perceptive quip. If he was able to comment on the global water situation today, he might add “I guess so, I dunno“.
This is the first in a series of posts on underground water, or groundwater. The posts will outline, with a non-specialist perspective, the science of aquifers, groundwater movement, how groundwater interacts with surface water, water extraction-pumping, and contamination. Continue reading →
If you haven’t already done so, have a read of this Editorial from Scientific American. It concerns the state of science and anti-science in American politics in general, and the current election campaign in particular. And before you write this off as the meanderings of a bunch of elite, leftist twits, consider that Scientific American has been publishing since 1845, and has been at the forefront of patenting and technology advancement for over 170 years. Sci Am has an enviable reputation for espousing scientific values, scientific thinking, and the kind of creativity that gives rise to discoveries that help improve humanity’s lot.
Scientific journals like Scientific American rarely if ever contribute comments to political debates unless they are responding to specific scientific or technological questions or issues. So for Sci Am to comment in this manner is unusual to say the least. I encourage people to read and think about the issues stated here for two primary reasons:
1. That it cuts to the core of science and the integrity of science (industry in the broadest sense would simply not exist without science and technology); and
2. This issue is not just the purview of American politics (in the most general terms) but concerns politics in many other nations, my own countries (New Zealand and Canada) included, where evidence-based policy, debate, and argument is increasingly taking a back seat to the shallowness of popularity and superficial comment.
The issue(s) stated in the Editorial go beyond party politics. There are many scientific issues that require reasoned debate and comment – issues around medical, environmental and genetic engineering science, to name just three, that impact not just the way science is conducted, but the way we think about human values, ethics, and beliefs. Scientific knowledge is crucial.
Sam had the day off so the two of us headed to Raglan and Ngarunui Beach, a typical wild, west coast North Island beach that includes a world class left-hand surf break at Manu Bay. Continue reading →
The expression global extinction frequently conjures images of all life being snuffed out by an act of celestial hubris. Asteroids, bolides or comets can be lobbed our way at whim. Earth, in its first billion years or so was probably hammered by extra-terrestrial bits of rock and ice. The cratered surface of our moon attests to this. Some argue that it was these early collisions that provided at least some of our water and possibly even the organic compounds that eventually gave rise to life itself. Continue reading →
Cycle: ( noun) A series of events that are regularly repeated in the same order (Oxford Dictionary)
How Milankovitch cycles effect Earth’s climate
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 →
