Remote sensing of active volcanism: For the past three years at the University of Alaska Fairbanks I have been involved in research pertaining to remote sensing of active volcanism. Remote sensing in this business is just another term for satellite imaging, and I concentrate on thermal imagery as opposed to radar imagery. The qualifier 'active' is provided to indicate that we're looking at recent or ongoing volcanism, and not million year old pyroclastics. UAF has provided the perfect environment for my endeavors in this field - an amazing diversity of nearby active volcanoes, an established remote sensing monitoring program through the Alaska Volcano Observatory, and a lot of intriguing scientific questions remaining to be answered. Being a part of AVO has provided experience in real-time satellite monitoring that I don't believe could be garnered anywhere else. Pouring over thousands and thousands of AVHRR images over the past three years as a result of our daily monitoring shifts, one gets an innate feel for thermal imagery that you just can't get any other way. Nonetheless, I've decided to broaden my horizons further and move on to the University of Hawaii Manoa for my Ph.D., under the guidance of Andrew Harris.
|AVHRR of Okmok eruption||AVHRR band 4-5 of Cleveland eruption|
The particular projects that I've been working on, and will be working on during the next few years, can be divided into a few categories:
Lava flow cooling: My master's thesis is titled 'Numerical Modeling of Lava Flow Cooling Applied to the 1997 Okmok Eruption: Comparison with AVHRR Thermal Imagery". I developed a model for static lava flow cooling, concentrating on extended cooling periods, and applied it to the basalt a'a flow erupted in Okmok caldera during its 1997 eruption. I then compared the predictions to AVHRR measurements of the flow surface throughout the flow's cooling period (ranging from 200 days to 4 years). The full text of my thesis, in PDF format, can be found here. This project was challenging because it required addressing and understanding the details of a variety of seemingly disjoint areas. For instance, one day I might be familiarizing myself with the thermal conductivity change of basalt with temperature, or the distribution of latent heat generation between the solidus and liquidus, and the next day I would be trying to establish the ground sample distance and instantaneous field of view for AVHRR at varying scan angles. Needless to say, I learned a lot.
|Landsat of Okmok caldera||The 1997 Okmok lava flow||Forward Looking Infrared Radiometer image of 97 flow, still hot in 2001|
Strombolian eruptions: Stromboli volcano, in the Aeolian Islands of Italy, is a unique volcano due to its impressive consistency of eruptive activity. For about the last 2000 years, Stromboli has experienced intermittent eruptions at a fairly regular frequency - usually amounting to at least a few every hour. Couple this dependability with the ease of access to, and relative safety of, the summit (certainly more so than Aleutian volcanoes) and you get a near-perfect laboratory to study an eruptive behavior (Strombolian activity) that is less-predictably present at many other of the world's volcanoes.
In May 2002, I accompanied my committee member Jonathan Dehn to Stromboli, joining Andy Harris from University of Hawaii Manoa and Maurizio Ripepe from University of Florence, among many others, for a month of field work that brought together several tools (seismic, infrasound, infared radiometery and our Forward Looking Infrared Radiometer (FLIR)), to simultanously record the attributes of Strombolian eruptions.
|The FLIR camera||Eruption from Crater 3, May 2002 (Jon Dehn, AVO)||Eruption from Crater 3, May 2002 (Jon Dehn, AVO)||FLIR image of a gassy eruption||FLIR image of a spatter eruption|
Mud volcanism: It sounds like an obscure topic of research, but mud volcanism is surprisingly common throughout the world. In my work, I used Landsat 7 ETM+ imagery to extract heat and mass flux information from two active mud volcanoes in Alaska.
Two groups of mud volcanoes are located in the Copper River Basin in southcentral Alaska: the Drum and Tolsona groups. The Drum group is isolated, and genetically distinct, from the Tolsona group of mud volcanoes which is approximately 55 km west. The Drum group emits hot mud and predominantly carbon dioxide gas and is believed to be linked to subsurface heating of carbonate sediments by a shallow magma body (Wescott and Turner, 1985; Motyka et al., 1986), while the Tolsona group erupts cold mud and mostly methane gas and is probably the surface manifestation of hydrocarbon degassing at depth (Reitsema, 1979). These two locales are representative of the dichotomous grouping of mud volcanism worldwide: those resulting from magmatic heating and those with a hydrocarbon origin. Mud volcanoes originating from magmatic heating can be found in locales including Yellowstone, California, Nevada and Japan, and those from hyrdrocarbon alteration in Central and South America, Azerbaijan and China. Hydrocarbon mud volcanism usually results in cold mud (except in cases where the erupting hydrocarbon- rich mud ignites, as happens in Azerbaijan), and is not amenable to thermal satellite observation. This study focuses on the thermal analyses of mud volcanoes, and is relevant only to those which erupt significantly heated mud.
The mud volcanoes studied here include the members of the Drum group (see below), which include Upper and Lower Klawasi and Shrub. Upper and Lower Klawasi mud volcanoes measure 90 and 45 meters in height, and have summit crater diameters of 45 and 53 meters, respectively. The Klawasi mud volcanoes have been continuously active since the 1950's, with active mud upwelling confined to well-defined central craters (Motyka et al., 1986). The Shrub edifice is approximately 95 meters above the surrounding terrain, and erupts mud out of numerous, isolated small pools (<5 meter diameter). Largely inactive since the 1950's, Shrub's quiescence abruptly ended with a vigorous eruption in the spring of 1997 which continued through 2000. Mud was erupted to a height of 5 meters, and large amounts of carbon dioxide poured down the flanks killing nearby vegetation and animal life (Richter et al., 1998).
|Upper Klawasi mud volcano (Game McGimsey, USGS)||Landsat ETM+ Band 6 of Upper Klawasi||Lower Klawasi mud volcano (Game McGimsey, USGS)||Landsat ETM+ Band 6 of Lower Klawasi|