<div class="cbp-l-inline"><img src="/explorations/10sanandreas/logs/media/sparkler-500.jpg" alt="Jackson Currie and Sam Johnson from USGS prepare the “mini-sparker” for deployment. The “mini-sparker” sends out a “shot” every half or one second depending on water depth, and the sound of the shot bouncing back helps determine the hardness of the subsurface layers of the ocean bottom. Data from the “mini-sparker” creates an image of the cross section of the fault, revealing the structure of the fault and sediments surrounding it." title="Mini-sparker"></div><div class="cbp-l-inline-below"><div class="cbp-l-inline-title"><span class="glyphicon glyphicon-picture" aria-hidden="true"></span>&nbsp;Mini-sparker</div><div class="cbp-l-inline-subtitle"><em>Image courtesy of San Andreas Fault 2010 Expedition, NOAA-OER.</em> <a href="/explorations/10sanandreas/logs/summary/media/sparkler-500.jpg.jpg" download>Download image (jpg, 133 KB).</a></div><div class="cbp-l-inline-desc"><p>Jackson Currie and Sam Johnson from USGS prepare the “mini-sparker” for deployment. The “mini-sparker” sends out a “shot” every half or one second depending on water depth, and the sound of the shot bouncing back helps determine the hardness of the subsurface layers of the ocean bottom. Data from the “mini-sparker” creates an image of the cross section of the fault, revealing the structure of the fault and sediments surrounding it.</p></div><div class="cbp-l-inline-view-wrap"><a href="/explorations/10sanandreas/logs/summary/summary.html" class="cbp-l-inline-view">Learn more</a></div></div>