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Thursday, October 27, 2011

Changes Coming to Maps of Japan

Because of the upheaval of the March 11, 2011 9.0 Magnitude earthquake, official maps of Japan will have to be altered. 
While the average person will not need to go out and purchase these new maps for travel purposes, the changes are significant enough for the map makers looking for something to do.

As part of Japan's map-making, there are tens of thousands of map points that have been measured and charted - some for as long as a century - that are part of the country's surveying, charting and map-making industry, 
Thanks to the big earthquake that affected the northeast part of Japan, it has been noted that there has been a huge shift of these points and intersections throughout the country - huge for a surveyor/mapmaker - that has only been seen once previously in Japan's history. 
(I should note that the article I saw this in did not state when that previous earth shift was!)
Now... to be fair, and a bit more serious, that bloody earthquake moved the coastline (that's what many earthquakes do) and changed the balance of the planet.

Reports indicate that, according to GPS (global positioning stations) closest to the epicenter have moved east by as much as 13 feet.

According to Ross Stein, a geophysicist at the United States Geological Survey, Japan is "wider than it was before."

Of course, not all of Japan moved 13-feet - just those areas closest to the epicenter. Areas farther away did move, just not as much. 

Usually, with tectonic plate shifts, the east part of Japan pushes westward thanks to pressure from the American plate and causes the plate to buckle as one plate slides under the other - meaning that an earthquake doesn't usually cause Japan to move one way or the other too much.

However, after the March 11, 2011 earthquake, Japan snapped back eastward, pushing itself a little bit closer to the U.S. by 13-feet.  

(Ed. Note... using your thumb and forefinger, hold a playing card... now squeeze. This middle will rise until the card pops from your grasp. This is what happens when tectonic plates compress. Pop! In this case, the card flew to the right. For this blog, look at the photo above of someone bending a microchip)   

As it unbuckled, a 250-mile-long coastal section of Japan dropped in altitude by two feet, which allowed the tsunami to travel farther and faster onto land.
For map makers, Japan’s central measuring point from which all other measuring points radiate is located in a small Greco-Roman stone building in a public park in Tokyo. Reports indicate that it sank an unprecedented 2.4 centimeters (1 inch).

Locally in Japan, Toyko's Azabu ward and parts of the Chiyoda ward have shifted eastward.

After the Japanese government enacted a new Land Survey Act to revise Japan’s leveling and geodetic datum, the Geospatial Authority of Japan, announced that 109,000 trigonometric points and 18,000 level points for surveying throughout Japan will change as a result of the extensive geodetic shift (earthquake's aftermath).

That means new maps with new elevations, coastlines and such.

By Andrew Joseph

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