The Honolulu Star-Advertiser (http://is.gd/Znefqz) says geophysicists in Hawaii and Texas have been looking at how the volcanoes are linked and yet have distinct and separate eruptions.
For instance, the U.S. Geological Survey says between 1934 and 1952, only Mauna Loa was active. But between 1952 and 1974 only Kilauea was active. However, global positioning records show that between 2003 and 2007 they both bulged upward due to the pressure of rising magma.
Helge Gonnermann, an assistant professor of Earth science at Rice University in Houston, says there appears to be a lag time as the pressure is transmitted slowly through partially molten material 50 miles below the Earth's crust.
Information from: Honolulu Star-Advertiser, http://www.staradvertiser.com