Popping rocks mystery solved

<body leftmargin="0" bgcolor="#000060" text="#FFFFFF" link="#FFFF00" vlink="#FF9900"> <table border="0" cellpadding="0" cellspacing="0" width="95%" height="1"> <tr> <center> <td valign="top" width="33%" height="33"> <b> <p class="MsoNormal"><font face="Arial" size="5">“Popping rocks” mystery solved</font></p> </b> <p class="MsoNormal"><font face="Arial" size="1">June 6, 2005<br> Courtesy Proceedings of the National Academy of Sciences<br> and World Science staff </font> </p> <p class="MsoNormal"> <b><font size="2" face="Arial">Scientists say they have rediscovered a lost geological treasure: the popping rocks of Guadalupe Island.<br> <br> In 1960, oceanographer Dale Krause reported finding deep-sea volcanic rocks in waters off Mexico, near Guadalupe Island, about 200 miles south of San Diego, headquarters of the Scripps Institution of Oceanography where he worked.<br> <br> When brought to the surface, the rocks exploded “with a sharp snapping sound,” according to Krause. <br> <br> Since then, a few other sites, mostly along the Mid-Atlantic Ridge, have been reported with similar “popping rocks.” An attempt by the late Scripps Professor Harmon Craig to locate the site in 1984 proved unsuccessful, largely because the location of the original discovery lacked the precision of today’s navigational technologies. <br> <br> A team of U.S. and Mexican geologists and students aboard the institution’s Revelle research vessel expedition explored the region early this month, including the area now known as Popcorn Ridge. The mission was aimed at locating the rocks and with them, unique information they could provide about Earth processes. <br> <br> On Oct. 9, the fifth day of the six-day expedition, the researchers hit the jackpot along the flank of what the scientists are now calling Krause Volcano. <br> <br> “As soon as we took the rocks out of the water we could hear them popping, much like a firecracker,” said Barry Eakins, a post-doctoral researcher at Scripps and one of the chief scientists on the cruise. “We knew this was a big find.” <br> <br> Eakins and co-chief scientist Dana Vukajlovich, a Scripps graduate student, say the loud popping sounds are due to high concentrations of volcanic gases trapped in bubbles within the lava rocks that explode when they escape the confining water pressure of the deep ocean floor. <br> <br> The scientists say the rediscovery will give them the opportunity to study these rare rocks in their Scripps laboratories and to compare them with popping rocks from the Mid-Atlantic Ridge. <br> <br> Vukajlovich said the rocks are important because the volcanic gases such as carbon dioxide, water vapor, helium and argon that are trapped in the bubbles did not escape during eruption and therefore should represent the concentrations of these gases in Earth’s mantle, the layer of Earth between the crust and the core. <br> <br> Eakins believes this will give researchers more information about the inventory of these gases within Earth and help them better understand the origin and history of Earth’s atmosphere. “These rocks will be the source of research for decades,” Eakins said. </font></b> </p> <b> <p><font face="Arial" size="2">* * *</font></p> </b> <p><b><font face="Arial" size="2" color="#FFFFFF">Send us a <a href="mailto:editor@world-science.net">comment</a> on this story, or <a href="mailto:?Body=http://www.world-science.net/othernews/051018_poprocksfrm.htm">send it to a friend</a></font></b> </p> <p> </center> </td> </tr> </table> </body>