Science. 1979 May 4;204(4392):495-7. doi: 10.1126/science.204.4392.495.
Large teleseismic delays, exceeding 1 second, are found near Mount Hannah in the Clear Lake volcanic field and in the steam-production area at The Geysers. The delays are superimposed on a general delay field of about 0.5 second extending over the volcanic rocks and the steam reservoir. It is postulated that a magma chamber under the surface volcanic rocks with a core of severely molten rock beneath Mount Hannah and a highly fractured steam reservoir probably underlain by partially molten rock at The Geysers are responsible for the observed delays. Both zones extend to depths of 20 kilometers or more.
在克利尔莱克火山区的汉纳山附近和间歇泉区的蒸汽生产区，发现了长达 1 秒以上的大型远程地震延迟。这些延迟叠加在一个大约 0.5 秒的总延迟场之上，该延迟场延伸到火山岩和蒸汽储层。推测认为，表面火山岩下的一个岩浆室，其核心是汉纳山下方严重熔融的岩石，以及一个可能部分熔融岩石下的高度破碎的蒸汽储层，可能是造成观察到的延迟的原因。这两个区域都延伸到 20 公里或更深的深度。
