Mauna Loa Swanson Feb 2002.jpg (53243 bytes)

Snow capped Mauna Loa Volcano, Hawaii, February 2002. U.S. Geological Survey photo by Don Swanson. 13,680 feet high with a volume of 19,000 cubic miles, Mauna Loa is the worlds largest active volcano. It has recently begun to slowly swell from new magma being injected at depth beneath the volcano. Recent press reports of this precursory activity have been greatly exaggerated. The following quotation from the Hawaiian Volcano Observatory is a more sober assesment of the situation: "0605 October 19 There are no unexpected changes at Mauna Loa. Seismicity remains low on this Friday morning. The permanent, continuous GPS network indicates ongoing lengthening of a distance across the summit caldera (Moku`aweoweo). The lengthening started in late April or May, as did uplift also measured by GPS. We interpret the lengthening and uplift to indicate resumed swelling of the magma reservoir within the volcano. The following is an information statement issued by us on October 17: Various media reports over the past several days greatly exaggerate the Mauna Loa situation. On September 29, we issued a report in our weekly Volcano Watch series, viewable at, explaining that Mauna Loa has started to inflate. The situation today is exactly as described in that report. Nothing has changed, and there is no reason to envision “devastation without much warning,” as one story put it. The inflation will likely, but not certainly, culminate in an eruption, but it is impossible to say when that eruption might take place, where it might take place, how large it might be, how long it might last, or whether it might send lava into populated areas. It is well to remember that the past two eruptions of Mauna Loa, in 1975 and 1984, did no damage, but that the 1950 eruption did destroy property in parts of South Kona. It is also well to remember that Mauna Loa is not an explosive volcano, and that there have been no fatalities from any of the 33 Mauna Loa eruptions since 1843, when written records start. The September 29th report was fairly covered by Hawai`i’s media. It was not until a press release was issued by Stanford University (a scientist at Stanford has loaned auxiliary equipment for our use to monitor Mauna Loa) at the end of last week that the national media became interested, and subsequent stories have blown the situation far out of proportion. Paraphrased comments made by an HVO scientist have been packaged in a doom-and-gloom context to make an unnecessarily alarming, splashy story. Unfortunately, some local media have even picked up on these exaggerated accounts. We recommend that you read our report mentioned above and disregard the misleading and inflammatory recent statements. As we stated in that report, “we will report any significant changes as they take place via both the media and our web site (”