Radar in archaeology

(SFX: Indiana Jones music, quote"throw me the whip!...")

     WHILE A WHIP MAY HAVE BEEN ALL INDIANA JONES NEEDED TO UNCOVER 
ANCIENT TREASURE, MOST ARCHAEOLOGISTS RELY ON  MORE HI-TECH 
TOOLS, SUCH AS RADAR. ARCHAEOLOGIST LARRY CONYERS OF THE UNIVERSITY OF 
COLORADO HAS BEEN USING SOMETHING CALLED GROUND PENETRATING RADAR TO
INVESTIGATE THE VILLAGE OF CEREN, EL SALVADOR, WHICH HAS BEEN BURIED UNDER
MORE THAN 15 FEET OF VOLCANIC ASH FOR NEARLY 1400 YEARS.

     Conyers: "Ground-penetrating radar is ...very similar to radar that you would use to look for
airplanes in the sky or ships at sea, except in this case...you shoot radar pulses into the ground."

     THE PULSES EASILY PASS THROUGH THE VOLCANIC ASH BUT REFLECT OFF OF
ANYTHING HARDER - LIKE BURIED ARTIFACTS.  THE RADAR WAVES BOUNCE BACK TO
THE SURFACE WHERE A COMPUTER ANALYZES THEM AND CREATES A TWO-DIMENSIONAL MAP OF THE TOWN. SINCE THE  ASH IS VIRTUALLY TRANSPARENT TO THE
RADAR, CONYERS AND HIS TEAM HAVE BEEN ABLE TO IDENTIFY BUILDINGS, COLUMNS,
AND EVEN FURROWS IN AN ANCIENT CORNFIELD, ALL WITHOUT LIFTING A SHOVEL. 

     Conyers: "Without this kind of geophysical tool we'd have to get in there with back hoes...and
each one of those test pits that we'd have to dig down might take a week and 3 or 4 laborers...It's
expensive, it's time-consuming, and it's a big pain."

     EXCAVATIONS REVEAL THAT VILLAGERS HAD JUST FINISHED THEIR EVENING
MEAL WHEN A POWERFUL TREMOR SHOOK POTS OFF SHELVES AND CRACKED HOUSE
WALLS. DOWNPOURS SOAKED VILLAGERS AS THEY FLED TO ESCAPE THE ERUPTION,
LEAVING BEHIND EVERYTHING THEY OWNED. 

     Conyers: "One would hope that they all escaped with their lives, fortunately for the
archaeologists, they did not escape with all of their possessions because they're still there for us to
study."