Downloaded from specialpapers.gsapubs.org on March 5, 2012 Geological Society of America Special Papers NASA volcanology field workshops on Hawai'i: Part 2. Understanding lava flow morphology and flow field emplacement Peter J. Mouginis-Mark, Sarah A. Fagents and Scott K. Rowland Geological Society of America Special Papers 2011;483;435-448 doi: 10.1130/2011.2483(26) Email alerting services click www.gsapubs.org/cgi/alerts to receive free e-mail alerts when new articles cite this article Subscribe click www.gsapubs.org/subscriptions/ to subscribe to Geological Society of America Special Papers Permission request click http://www.geosociety.org/pubs/copyrt.htm#gsa to contact GSA Copyright not claimed on content prepared wholly by U.S. government employees within scope of their employment. 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Notes © 2011 Geological Society of America Downloaded from specialpapers.gsapubs.org on March 5, 2012 The Geological Society of America Special Paper 483 2011 NASA volcanology fi eld workshops on Hawai‘i: Part 2. Understanding lava fl ow morphology and fl ow fi eld emplacement Peter J. Mouginis-Mark1,†, Sarah A. Fagents1, and Scott K. Rowland2 1Hawaii Institute of Geophysics and Planetology, University of Hawaii, Honolulu, Hawaii 96822, USA 2Geology and Geophysics Department, University of Hawaii, Honolulu, Hawaii 96822, USA ABSTRACT The Big Island of Hawai‘i presents ample opportunities for young planetary volcanolo- gists to gain fi rsthand fi eld experience in the analysis of analogs to landforms seen on Mercury, Venus, the Moon, Mars, and Io. In this contribution, we focus on a subset of the specifi c features that are included in the planetary volcanology fi eld workshops described in the previous chapter in this volume. In particular, we discuss how remote- sensing data and fi eld localities in Hawai‘i can help a planetary geologist to gain exper- tise in the analysis of lava fl ows and lava fl ow fi elds, to understand the best sensor for a specifi c application, to recognize the ways in which different data sets can be used syn- ergistically for remote interpretations of lava fl ows, and to gain a deeper appreciation for the spatial scale of features that might be imaged in the planetary context. INTRODUCTION these features with planetary analogs in state-of-the-art remote- sensing images. Rowland et al. (2011, Chapter 25, this volume) described The participants covered a wide range of disciplines during the background and history of the 10 planetary volcanology the workshop, including physical volcanology (Francis, 1993; fi eld workshops that have been held on the island of Hawai‘i Kilburn and Luongo, 1993; Parfi tt and Wilson, 2008), planetary since 1992. These workshops have provided an opportunity for remote sensing (Pieters and Englert, 1993; Mouginis-Mark more than 130 young National Aeronautics and Space Admin- et al., 2000; Campbell, 2002), and volcanism on the planets istration (NASA)–funded graduate students, postdoctoral fel- (McGuire et al., 1996; Zimbelman and Gregg, 2000; Lopes and lows, and junior faculty to view basaltic volcano features up Gregg, 2004; Keszthelyi et al., 2006; Lopes and Spencer, 2007). close, in the company of both terrestrial and planetary volca- It is also hoped that they gained some familiarity with the theo- nologists. The goal for each workshop was to give these young retical aspects of volcanism on the Moon (Wilson and Head, scientists a strong background in basaltic volcanology, and to 1981), Mars (Wilson and Head, 1994), and Venus (Head and provide the chance for them to view eruptive features up close Wilson, 1986, 1992). Thus, the range of topics that they studied so that the participants can then compare the appearance of in the fi eld in one short week was a mixture of geology, sensor †[email protected]. Mouginis-Mark, P.J., Fagents, S.A., and Rowland, S.K., 2011, NASA volcanology fi eld workshops on Hawai‘i: Part 2. Understanding lava fl ow morphology and fl ow fi eld emplacement, in Garry, W.B., and Bleacher, J.E., eds., Analogs for Planetary Exploration: Geological Society of America Special Paper 483, p. 435–448, doi:10.1130/2011.2483(26). For permission to copy, contact [email protected]. © 2011 The Geological Society of America. All rights reserved. 435 Downloaded from specialpapers.gsapubs.org on March 5, 2012 spe483-01 page 436 436 Mouginis-Mark et al. technology, and planetary exploration. To help the reader here, Viewing active lava fl ows was an additional aid to work- we provide a summary of the sensors used during the work- shop participants because they gained fi rsthand knowledge of shop, along with the appropriate planetary/terrestrial analog the temperature distribution of the surface of an active fl ow, instruments, and the wavelength range and spatial resolution of as well as the speed at which such fl ows can move (Lipman the sensors (Table 1). and Banks, 1987; Kilburn and Luongo, 1993). This knowledge In this contribution, we focus on some specifi c planetary ana- could then be employed in the planetary context for modeling log fi eld sites developed for the workshops to aid in the interpreta- the emplacement of lava fl ows on the Moon (Schaber, 1973; tion of lava fl ows and lava fl ow fi elds. Over the course of 3 days Hulme and Fielder, 1977), Mars (Wadge and Lopes, 1991; in the fi eld, we illustrated the level of diffi culty that is involved in Glaze et al., 2009), or Venus (Roberts et al., 1992; Lancaster mapping the spatial extent and other physical attributes of a lava et al., 1995), and it can help to interpret the duration of erup- fl ow fi eld. In the planetary context, mapping an entire lava fl ow is tions (Keszthelyi and Pieri, 1993; Mouginis-Mark and Yosh- important because, together with an estimate of fl ow thickness, it ioka, 1998). Knowledge of terrestrial lava fl ows can aid the provides a measure of the volume of lava erupted and some of the interpretation of active effusive volcanism on Io (Williams processes that control fl ow emplacement (Moore, 1987; Baloga et al., 2001). In each day in the fi eld, use was made of the abun- et al., 2003). Use of thermal infrared data that highlight the sur- dant remote-sensing data that have been collected for Hawai‘i face glass coatings of different Mauna Loa lava fl ows (Kahle et over the years, including high-resolution (1 m/pixel) visible al., 1988) was particularly helpful for correlating multiple fl ow images, thermal infrared images (Kahle et al., 1988, 1995), and lobes from a single eruption, and thus determining the length of radar data (Gaddis et al., 1989; Campbell et al., 1993). each lava fl ow. It was also important to identify the surface rough- ness differences between the two principal types of lava fl ows, REMOTE-SENSING IMAGES OF LAVA namely, relatively rough ‘a‘ and relatively smooth phoehoe, FLOW FIELDS because these differences relate to the fl ow rate at which the lava is erupted; ‘a‘ fl ows are erupted at high rates (>~20 m3 s–1), and A major goal of the workshops was and is to permit the attend- phoehoe are erupted relatively low rates (<~5m3 s–1) (Rowland ees to study volcanic landforms in the fi eld while viewing the same and Walker, 1990). An understanding of the discharge rate for landforms in remote-sensing data that are analogous in spatial or planetary lava fl ows and total fl ow volume is important for inter- spectral characteristics of planetary images. This provides the par- preting the subsurface structure of a volcano (Wilson and Head, ticipants with a greater familiarity with the strengths and weak- 1994; Head and Wilson, 1992), and so the workshop participants nesses of different sensors (optical, thermal, and radar) for mapping learned how to use orbital data to make inferences about the sub- landforms and a greater understanding of volcanic processes, as surface structure of a planetary volcano from the distribution well as an understanding of the spatial resolution of each instru- of lava fl ow types. The utility of multiparameter (i.e., different ment. Such an approach is particularly helpful when the wavelength wavelengths and different polarizations) imaging radar data for of the sensor is outside the optical region of the spectrum. surface roughness studies was also explored, particularly in the The interpretation of lava fl ow textures observed on Venus by context of studying lava fl ows on Venus, where the thick atmo- the Magellan radar (Fig. 1) and mapping of individual long lava sphere precludes optical imaging of the surface. fl ows within Mare Imbrium on the Moon (Fig. 2) are particularly TABLE 1. REMOTE-SENSING DATA SETS FOR THE EARTH AND OTHER PLANETS Acronym Sensor full name Platform Planet Resolution Wavelength AIRSAR AIRcraft Synthetic Aperture Radar Aircraft Earth 5 m 5.7, 25.0, and 68.0 cm ALOS