The technique's spatial coverage is variable from hundreds of square meters to hundreds of square kilometers. A technique has emerged that enables scientists to create an image of where and how much displacement occurred over a ground or glacial (ice) surface (e.g., Rosen and others, 2000). The images were produced from data acquired by the European Space Agency's Environmental Satellite (ENVISAT), with an incidence angle of 25° from the ground, looking W to E. As depicted in the scale bar (bottom center), concentric and cyclical sets of fringes indicate a ground movement of 2.83 cm towards the satellite's line-of-sight during the time interval shown in each image. The large number of color bands ('fringes') in (a) indicates an increased rate of inflation compared to the fewer number of fringes in (b). These interferograms highlight the slowing of inflation during the latter interval. Radar interferograms of Mauna Loa covering the time intervals of (a) 11 October 2003-19 November 2005 and (b) 24 March 2007-17 April 2010. To better understand the technique used to observe the slowed rate of deformation at Mauna Loa, see the next section.įigure 24. Comparison of radar interferograms covering two intervals (11 October 2003-19 November 2005 and 24 March 2007-17 April 2010) highlights the slowed deformation rates during the latter interval (figure 24). Increased rates of inflation following the April-October 2004 deep LP earthquake swarm continued through 2007, when HVO reported that GPS and InSAR-based inflation rates had slowed substantially. A subsection below discusses the use of deformation data as a basis for modeling inferred magma bodies in the subsurface at Mauna Loa (Amelung and others, 2007). The material in this report is drawn from monitoring data collected by the USGS Hawaiian Volcano Observatory (HVO) and, in particular, Interferometric Synthetic Aperture Radar (InSAR) data provided by HVO's Mike Poland. During 2004-2010, HVO reported little variation in gas emissions at Mauna Loa. ![]() After that and through 2010, deformation continued at variable rates and with brief pauses. We previously reported on an April-October 2004, deep, long-period (LP) earthquake swarm and associated brief period of contraction ( BGVN 29:09). Mauna Loa has remained non-eruptive since April 1984. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawaiʻi and American Samoa.2004-2010 deformation trends intrusive bodies modeled The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. This notice contains volcanoes not displayed here: Hualalai (NORMAL/GREEN), Haleakala (NORMAL/GREEN), Mauna Kea (NORMAL/GREEN), Kama'ehuakanaloa (UNASSIGNED/UNASSIGNED). Mauna Loa activity summary also available by phone: (808) 967-8866.Since its first well-documented eruption in 1843, the volcano has erupted 34 times with intervals between eruptions ranging from months to decades. Mauna Loa eruptions typically start at the summit and, within minutes to months of eruption onset, can migrate into either the Northeast or Southwest Rift Zone, or radial vents on the north flank. Eruptions tend to produce voluminous, fast-moving lava flows that can impact communities on the east and west sides of the Island. HVO continues to monitor the volcano closely and will issue another update in one month, or earlier should conditions change significantly.īackground: Mauna Loa is the largest active volcano on our planet and covers half of the Island of Hawaiʻi. Gas and temperature data from a station on the Southwest Rift Zone showed no significant changes over the past month. The largest earthquake for Mauna Loa over the past month was a M3.9 event that occurred during a small swarm on the Kaʻōiki Pali (southeast flank) on March 23 most events during the swarm occurred at depths ranging from 2 km (1.2 mi) above sea level to 8 km (5 mi) below sea level.ĭata from Global Positioning System (GPS) instruments on Mauna Loa indicate slow inflation as magma replenishes the summit reservoir system. The number of detected earthquakes remained at background levels and most events were smaller than M2.0. ![]() ![]() No significant activity was detected at Mauna Loa volcano during the past month. HAWAIIAN VOLCANO OBSERVATORY MONTHLY UPDATE Alert Level: NORMAL, Color Code: GREEN 19:26:12 UTC
0 Comments
Leave a Reply. |