Land is not supposed to rise this fast. Generations of geologists have been trained to think in terms of slow and steady processes to explain Earth features. New results show that the continental crust underlying Antarctica is rising rapidly as parts of its massive ice sheet have been melting away. This unexpected bounce might help better position the timing of similar effects that occurred in northern North America near the close of the Ice Age.
Since 1995, entire ice shelves the size of cities have been falling from the Northern Antarctic Peninsula into the sea. The land below that ice has been moving up to elevations where only ice once lay.1
A European team used satellites to track Antarctica's up-and-down motion, publishing their results in Earth and Planetary Science Letters.2 A Newcastle University press release said, "the land in this region is actually rising at a phenomenal rate of 15mm a year—much greater than can be accounted for by the present-day elastic response alone."3 The team investigated reasons why it has been rising so quickly.
Their answer points to the mantle deep below the crust. Temperature or chemical composition differences could get mantle material—circulating 250 miles below the surface—flowing more smoothly than expected. Its viscosity, or resistance to flow, is somehow ten times lower there than other zones beneath Antarctica.
Lead researcher Grace Nield told Newcastle University, "You would expect this rebound to happen over thousands of years and instead we have been able to measure it in just over a decade. You can almost see it happening which is just incredible."3 Why would she expect major earth movements to take thousands of years instead of the few dozen measured years? Could it be because of the relentless "old age" message she's undoubtedly heard from her textbooks and teachers all her life?
For example, standard uniformitarian ideas set the "timing" of the "last" Ice Age as closing between ten and twelve thousand years ago.4 Supposedly since then, northern ice regions have risen hundreds of feet as thick ice sheets melted and lightened the load.
Secularists estimated that land in the Hudson Bay area, where the ice sheet was thickest during the Ice Age, rose about 1,300 feet in the last 10,000 years.5 Today, viewers can see evidence of ancient lake shorelines, looking like giant bathtub rings, marked on Michigan area rocks. Routine teaching asserts that the area's uplift needed these thousands of years.
Even at the "phenomenal rate" of 15mm/year, Hudson Bay area's crustal rebound of 1,300 feet would still take close to 27,000 years—far too slow to account for secular estimates. Expressed another way, over 39mm/year are required to lift 1,300 feet of crust within the 10,000 years secularists insist elapsed since the Ice Age. This means that 15mm/year is way too slow to fit even the secular time frame applied to the Hudson Bay area.
This mismatch illustrates the futility of overlaying today's rates onto past events.
Clearly rebound rates were faster in the past—undoubtedly fast enough to accommodate even the Hudson Bay's remarkable rebound within the biblical timeframe.6 Thirteen hundred feet of rebound in approximately 4,000 years requires an initially phenomenal rebound rate. But, as this Antarctic study illustrates, "phenomenal" rates are beginning to be the norm.2
More research is needed to discover whether or not the mantle deep beneath portions of Michigan was ten times less viscous when those areas rebounded at the close of the Ice Age, but now we know with the precision that GPS technology affords that upward crustal motion can be much faster than previously thought. Rebound does not require the long ages that secular geological standards would lead us to expect in today's rocks, nor does it require long ages to explain yesterday's geology.
- Meanwhile, snow ice has been accumulating in regions nearer the North Pole. Has arctic crust been sinking as a result?
- Nield, G. A. et al. 2014. Rapid bedrock uplift in the Antarctic Peninsula explained by viscoelastic response to recent ice unloading. Earth and Planetary Science Letters. 397 (July): 32-41.
- Ice-loss moves the Earth 250 miles beneath our feet. Newcastle University. Posted on ncl.ac.uk May 12, 2014, accessed May 19, 2014.
- Jake Hebert. 2013. Was There an Ice Age? Acts & Facts. 42 (12): 20.
- Clark, J.A., et al. 1994. Glacial isostatic deformation of the Great Lakes region. Geological Society of America Bulletin. 106 (1): 19-31.
- Isostatic motion could have exceeded 15mm per year given other factors, like accelerated ice-melt rates.
* Mr. Thomas is Science Writer at the Institute for Creation Research.
Article posted on May 30, 2014.