Virginia Claire Gulick

Interests

Research

Fluvial and hydrothermal studies on Mars and Earth, Paleo-environmental and paleoclimatic change studies on Earth and Mars, Raman spectroscopy, Developing automated spectral and image classifiers and reasoning layers for planetary exploration and for use in terrestrial applications, Geomorphologic, hydrologic, hydrogeologic, and terrestrial analog studies, Automated science analysis tool development for online use, Collaborative interdisciplinary studies

Courses

Scholarly Contributions

Chapters

• Cady, S., Skok, J., Gulick, V., Berger, J., & Hinman, N. (2018). Siliceous Hot Spring Deposits: Why They Remain Key Astrobiological Targets. In From Habitability to Life on Mars. doi:10.1016/b978-0-12-809935-3.00007-4
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  For nearly 40 years, hydrothermal deposits have been recognized as potential paleobiological repositories for astrobiological exploration of Mars. Here, we summarize the motivation for this astrobiological search strategy as it pertains to our current understanding of silica-depositing hot spring ecosystems and terrestrial siliceous hot spring deposits. We also discuss the rover and orbital observations of recently discovered hydrothermal opaline silica deposits on Mars-interpreted as evidence of hot spring activity. The opaline silica digitate sinters near Columbia Hills represent the strongest evidence to date for potential fossilized biosignatures on Mars. The high habitability and preservation potentials of hot spring deposits on Earth, along with their ability to reveal insight into the metabolic evolution of life, strengthen the rationale for targeting siliceous hot spring deposits as high-priority astrobiology sites for future Mars missions.
• Hargitai, H. I., & Gulick, V. C. (2018). Chapter 4 - Late Amazonian–Aged Channel and Island Systems Located East of Olympus Mons, Mars. In Dynamic Mars(pp 121-154). Elsevier.

Journals/Publications

• McEwen, A., Byrne, S., Hansen, C., Daubar, I., Sutton, S., Dundas, C., Bardabelias, N., Baugh, N., Bergstrom, J., Beyer, R., Block, K., Bray, V., Bridges, J., Chojnacki, M., Conway, S., Delamere, W., Ebben, T., Espinosa, A., Fennema, A., , Grant, J., et al. (2024). The high-resolution imaging science experiment (HiRISE) in the MRO extended science phases (2009–2023). Icarus, 419. doi:10.1016/j.icarus.2023.115795
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  The Mars Reconnaissance Orbiter has been orbiting Mars since 2006 and has acquired >80,000 HiRISE images with sub-meter resolution, contributing to over 2000 peer-reviewed publications, and has provided the data needed to enable safe surface landings in key locations by several rovers or landers. This paper describes the changes to science planning, data processing, and analysis tools since the initial Primary Science Phase in 2006–2008. These changes affect the data used or requested by the community and how they should interpret the data. There have been a variety of complications to the dataset over the years, such as gaps in monitoring due to spacecraft and instrument issues and special events like the arrival of new landers or rovers on Mars or global dust storms. The HiRISE optics have performed well except for a period when temperature uniformity was perturbed, reducing the resolution of some images. The focal plane system now has 12 rather than 14 operational detectors. The first failure (2011) was a unit at the edge of the swath width, reducing image width by 10% rather than creating a gap. The recent (2023) failure was in the middle of the swath. An unusual problem with the analog-to-digital conversion of the signal (resulting in erroneous data) has worsened over time; mitigation steps so far have preserved full-resolution imaging over all functional detectors. Soon, full-resolution imaging will be narrowed to a subset of the detectors and there will be more 2 × 2 binned data. We describe lessons received for future very high-resolution orbital imaging. We continue to invite all interested people to suggest HiRISE targets on Mars via HiWish, and to explore the easy-to-use publicly available images.
• Hargitai, H. I., & Gulick, V. C. (2022). The channels East of Olympus Mons, Mars. Journal of Maps, 18(2), 413-417.
• Hinman, N. W., Hofmann, M. H., Warren-Rhodes, K., Phillips, M. S., Noffke, N., Cabrol, N. A., Chong, D. G., Demergasso, C., Tebes-Cayo, C., Cabestrero, O., Bishop, J. L., Gulick, V. C., Summers, D., Sobron, P., McInenly, M., Moersch, J., Rodriguez, C., Sarazzin, P., Rhodes, K. L., , Riffo, C., et al. (2022). Surface Morphologies in a Mars-Analog Ca-Sulfate Salar, High Andes, Northern Chile. Frontiers in Astronomy and Space Sciences, 8, 797591.
• Gulick, V. C., McEwen, A. S., Bishop, J. L., Yeşilbaş, M., Hinman, N. W., Burton, Z. F., Englert, P. A., Toner, J. D., Gibson, E. K., & Koeberl, C. (2021). Martian subsurface cryosalt expansion and collapse as trigger for landslides. Science Advances, 7(6). doi:10.1126/sciadv.abe4459
• Hinman, N. W., Bishop, J. L., Gulick, V. C., Dettmann, J., Morkner, P., Berlanga, G., Henneberger, R. M., Bergquist, P., Richardson, C. D., Walter, M. R., MacKenzie, L. A., Anitori, R. P., & Scott, J. R. (2021). Targeting mixtures of jarosite and clay minerals for Mars exploration. American Mineralogist, 106(8), 1237-1254.
• Johnsen, T. K., Marley, M. S., & Gulick, V. C. (2020). A Multilayer Perceptron for Obtaining Quick Parameter Estimations of Cool Exoplanets from Geometric Albedo Spectra. Publications of the Astronomical Society of the Pacific, 132(1010), 044502.
• Gulick, V. C., Glines, N., Hart, S., & Freeman, P. (2019). Geomorphological analysis of gullies on the central peak of Lyot Crater, Mars. Geological Society, London, Special Publications, 467(1), 233-265.
• Hargitai, H. I., Gulick, V. C., & Glines, N. H. (2019). Evolution of the Navua Valles region: Implications for Mars' paleoclimatic history. Icarus, 330, 91-102.
• Hargitai, H. I., Gulick, V. C., & Glines, N. H. (2018). Paleolakes of Northeast Hellas: Precipitation, Groundwater-Fed, and Fluvial Lakes in the Navua-Hadriacus-Ausonia Region, Mars.. Astrobiology, 18(11), 1435-1459. doi:10.1089/ast.2018.1816
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  The slopes of northeastern Hellas Basin, Mars exhibit a wide variety of fluvial landforms. In addition to the Dao-Niger-Harmakhis-Reull Valles outflow channels, many smaller channels and valleys cut into this terrain, several of which include discontinuous sections. We have mapped these channels and channel-associated depressions to investigate potential paleolakes from the Navua Valles in the West, through the Hadriacus Mons volcano in the center, to the Ausonia Montes in the East. We have identified three groups of candidate paleolakes at the source regions of major drainages and a fourth paleolake type scattered along the lower reaches of these drainages. Each paleolake group has a distinct character, determined by different formative processes, including precipitation and groundwater for lakes at the channel sources, and fluvially transported water at the lower channel reaches. Only one of these 34 basins had been cataloged previously in paleolake basin databases. Several of these sites are at proximity to the Hadriacus volcanic center, where active dikes during the Hesperian could have produced hydrothermal systems and habitable environments. Deposits within these paleolake depressions and at the termini of channels connected to these candidate paleolakes contain the geological and potentially biological record of these environments.
• Hargitai, H. I., Gulick, V. C., & Glines, N. H. (2018). The geology of the Navua Valles region of Mars. Journal of Maps, 14(2), 504-508.
• Hargitai, H., Gulick, V., & Glines, N. (2017). Discontinuous drainage systems formed by highland precipitation and ground-water outflow in the Navua Valles and southwest Hadriacus Mons regions, Mars. Icarus, 294, 172-200. doi:10.1016/j.icarus.2017.03.005
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  The Navua Valles are systems of paleodrainages located north of Dao Vallis, which empty into Hellas Planitia, the largest impact basin on Mars. In this study, we mapped and characterized the Navua Valles Region's individual drainage systems, including drainages along the southwestern flank of Hadriacus Mons, and one valley network from the same source as Navua Valles but flowing in the opposite direction. The major drainage systems share morphological characteristics common to both outflow channels and valley networks. The slopes in this region are dissected by two major Navua drainage systems (here Navua A* and B*) and several shorter, sub-parallel valleys formed on the highest gradient (approximately 20 m/km [1.15°]) slopes, at the lowest part of Hellas Basin's rim. The two major drainage systems originate in the highlands, and empty into the basin. Our mapping suggests that water in Navua Valles reached the basin floor in a complicated descent and included several episodes of surface ponding, surface runoff, infiltration, subsurface flow and subsequent outflow. The most prominent channel system, Navua A, forms a repetitive sequence of deep incision into bedrock, followed by a transition into broad channels in erodible materials, and then into unconfined deposits. This successive erosion–transport–deposition sequence continues to repeat along the valley's entire length forming a discontinuous pattern that is consistent with classical fluvial process models. The channels cut into volcanic plains likely emplaced from the formation of Tyrrhenus and Hadriacus Montes. The dendritic source valleys of Navua A originate from the rim of a highland crater while the rest of this subsystem consists of a single, discontinuous channel which is consistent with a single water source zone that likely supplied water for all channels downslope. These drainages may have formed as discontinuous channels, revealing the potential existence of subsurface drainage pathways located within an approximately 1.5 × 105 km2 area. Water transported underground emerged in segments that are either isolated or aligned downslope from each other. We have identified several causes of discontinuities, located the zones of potential ground-water discharge and recharge, and a site of localized precipitation at the headwaters of Navua A.
• Rodriguez, J., Fairen, A., Tanaka, K., Zarroca, M., Linares, R., Platz, T., Komatsu, G., Miyamoto, H., Kargel, J., Yan, J., Gulick, V., Higuchi, K., Baker, V., & Glines, N. (2016). Tsunami waves extensively resurfaced the shorelines of an early Martian ocean. Scientific Reports, 6. doi:10.1038/srep25106
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  It has been proposed that ∼3.4 billion years ago an ocean fed by enormous catastrophic floods covered most of the Martian northern lowlands. However, a persistent problem with this hypothesis is the lack of definitive paleoshoreline features. Here, based on geomorphic and thermal image mapping in the circum-Chryse and northwestern Arabia Terra regions of the northern plains, in combination with numerical analyses, we show evidence for two enormous tsunami events possibly triggered by bolide impacts, resulting in craters ∼30 km in diameter and occurring perhaps a few million years apart. The tsunamis produced widespread littoral landforms, including run-up water-ice-rich and bouldery lobes, which extended tens to hundreds of kilometers over gently sloping plains and boundary cratered highlands, as well as backwash channels where wave retreat occurred on highland-boundary surfaces. The ice-rich lobes formed in association with the younger tsunami, showing that their emplacement took place following a transition into a colder global climatic regime that occurred after the older tsunami event. We conclude that, on early Mars, tsunamis played a major role in generating and resurfacing coastal terrains.
• Rodriguez, J., Kargel, J., Baker, V., Gulick, V., Berman, D., Linares, R., Zarroca, M., Yan, J., Miyamoto, H., Glines, N., & Fairén, A. (2015). Erratum: Martian outflow channels: How did their source aquifers form, and why did they drain so rapidly? (Scientific Reports (2015) 5(13404) 10.1038/srep13404). Scientific Reports, 5. doi:10.1038/srep15092
• Rodriguez, J., Kargel, J., Baker, V., Gulick, V., Berman, D., Linares, R., Zarroca, M., Yan, J., Miyamoto, H., Glines, N., & Fairén, A. (2015). Martian outflow channels: How did their source aquifers form, and why did they drain so rapidly?. Scientific Reports, 5. doi:10.1038/srep13404
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  Catastrophic floods generated ∼3.2 Ga by rapid groundwater evacuation scoured the Solar Systems most voluminous channels, the southern circum-Chryse outflow channels. Based on Viking Orbiter data analysis, it was hypothesized that these outflows emanated from a global Hesperian cryosphere-confined aquifer that was infused by south polar meltwater infiltration into the planet s upper crust. In this model, the outflow channels formed along zones of superlithostatic pressure generated by pronounced elevation differences around the Highland-Lowland Dichotomy Boundary. However, the restricted geographic location of the channels indicates that these conditions were not uniform Boundary. Furthermore, some outflow channel sources are too high to have been fed by south polar basal melting. Using more recent mission data, we argue that during the Late Noachian fluvial and glacial sediments were deposited into a clastic wedge within a paleo-basin located in the southern circum-Chryse region, which was then completely submerged under a primordial northern plains ocean. Subsequent Late Hesperian outflow channels were sourced from within these geologic materials and formed by gigantic groundwater outbursts driven by an elevated hydraulic head from the Valles Marineris region. Thus, our findings link the formation of the southern circum-Chryse outflow channels to ancient marine, glacial, and fluvial erosion and sedimentation.
• Ishikawa, S., & Gulick, V. (2013). An automated mineral classifier using Raman spectra. Computers and Geosciences, 54, 259-268. doi:10.1016/j.cageo.2013.01.011
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  We present a robust and autonomous mineral classifier for analyzing igneous rocks. Our study shows that machine learning methods, specifically artificial neural networks, can be trained using spectral data acquired by in situ Raman spectroscopy in order to accurately distinguish among key minerals for characterizing the composition of igneous rocks. These minerals include olivine, quartz, plagioclase, potassium feldspar, mica, and several pyroxenes. On average, our classifier performed with 83 percent accuracy. Quartz and olivine, as well as the pyroxenes, were classified with 100 percent accuracy. In addition to using traditional features such as the location of spectral bands and their shapes, our automated mineral classifier was able to incorporate fluorescence patterns, which are not as easily perceived by humans, into its classification scheme. The latter was able to improve the classification accuracy and is an example of the robustness of our classifier. © 2013 Elsevier Ltd.
• McEwen, A., Ojha, L., Dundas, C., Mattson, S., Byrne, S., Wray, J., Cull, S., Murchie, S., Thomas, N., & Gulick, V. (2011). Seasonal flows on warm Martian slopes. Science, 333(6043). doi:10.1126/science.1204816
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  Water probably flowed across ancient Mars, but whether it ever exists as a liquid on the surface today remains debatable. Recurring slope lineae (RSL) are narrow (0.5 to 5 meters), relatively dark markings on steep (25° to 40°) slopes; repeat images from the Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment show them to appear and incrementally grow during warm seasons and fade in cold seasons. They extend downslope from bedrock outcrops, often associated with small channels, and hundreds of them form in some rare locations. RSL appear and lengthen in the late southern spring and summer from 48°S to 32°S latitudes favoring equator-facing slopes, which are times and places with peak surface temperatures from ∼250 to 300 kelvin. Liquid brines near the surface might explain this activity, but the exact mechanism and source of water are not understood.
• McEwen, A., Banks, M., Baugh, N., Becker, K., Boyd, A., Bergstrom, J., Beyer, R., Bortolini, E., Bridges, N., Byrne, S., Castalia, B., Chuang, F., Crumpler, L., Daubar, I., Davatzes, A., Deardorff, D., DeJong, A., Alan Delamere, W., Dobrea, E., , Dundas, C., et al. (2010). The High Resolution Imaging Science Experiment (HiRISE) during MRO's Primary Science Phase (PSP). Icarus, 205(1). doi:10.1016/j.icarus.2009.04.023
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  The High Resolution Imaging Science Experiment (HiRISE) on the Mars Reconnaissance Orbiter (MRO) acquired 8 terapixels of data in 9137 images of Mars between October 2006 and December 2008, covering ∼0.55% of the surface. Images are typically 5-6 km wide with 3-color coverage over the central 20% of the swath, and their scales usually range from 25 to 60 cm/pixel. Nine hundred and sixty stereo pairs were acquired and more than 50 digital terrain models (DTMs) completed; these data have led to some of the most significant science results. New methods to measure and correct distortions due to pointing jitter facilitate topographic and change-detection studies at sub-meter scales. Recent results address Noachian bedrock stratigraphy, fluvially deposited fans in craters and in or near Valles Marineris, groundwater flow in fractures and porous media, quasi-periodic layering in polar and non-polar deposits, tectonic history of west Candor Chasma, geometry of clay-rich deposits near and within Mawrth Vallis, dynamics of flood lavas in the Cerberus Palus region, evidence for pyroclastic deposits, columnar jointing in lava flows, recent collapse pits, evidence for water in well-preserved impact craters, newly discovered large rayed craters, and glacial and periglacial processes. Of particular interest are ongoing processes such as those driven by the wind, impact cratering, avalanches of dust and/or frost, relatively bright deposits on steep gullied slopes, and the dynamic seasonal processes over polar regions. HiRISE has acquired hundreds of large images of past, present and potential future landing sites and has contributed to scientific and engineering studies of those sites. Warming the focal-plane electronics prior to imaging has mitigated an instrument anomaly that produces bad data under cold operating conditions. © 2009 Elsevier Inc.
• Banks, M., McEwen, A., Kargel, J., Baker, V., Strom, R., Mellon, M., Gulick, V., Keszthelyi, L., Herkenhoff, K., Pelletier, J., & Jaeger, W. (2008). High Resolution Imaging Science Experiment (HiRISE) observations of glacial and periglacial morphologies in the circum-Argyre Planitia highlands, Mars. Journal of Geophysical Research: Planets, 113(12). doi:10.1029/2007JE002994
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  The landscape of the Argyre Planitia and adjoining Charitum and Nereidum Montes in the southern hemisphere of Mars has been heavily modified since formation of the Argyre impact basin. This study examines morphologies in the Argyre region revealed in images acquired by the High Resolution Imaging Science Experiment (HiRISE) camera and discusses the implications for glacial and periglacial processes. Distinctive features such as large grooves, semicircular embayments in high topography, and streamlined hills are interpreted as glacially eroded grooves, cirques, and whalebacks or roche moutonnée, respectively. Large boulders scattered across the floor of a valley may be ground moraine deposited by ice ablation. Glacial interpretations are supported by the association of these features with other landforms typical of glaciated landscapes such as broad valleys with parabolic cross sections and stepped longitudinal profiles, lobate debris aprons interpreted as remnant debris covered glaciers or rock glaciers, and possible hanging valleys. Aligned boulders observed on slopes may also indicate glacial processes such as fluting. Alternatively, boulders aligned on slopes and organized in clumps and polygonal patterns on flatter surfaces may indicate periglacial processes, perhaps postglaciation, that form patterned ground. At least portions of the Argyre region appear to have been modified by processes of ice accumulation, glacial flow, erosion, sediment deposition, ice stagnation and ablation, and perhaps subsequent periglacial processes. The type of bedrock erosion apparent in images suggests that glaciers were, at times, wet based. The number of superposed craters is consistent with geologically recent glacial activity, but may be due to subsequent modification. Copyright 2008 by the American Geophysical Union.
• Byrne, S., Gulick, V. C., McEwen, A. S., Hansen, C. J., Delamere, W. A., Eliason, E. M., Herkenhoff, K. E., Keszthelyi, L., Kirk, R. L., Mellon, M. T., Grant, J. A., Thomas, N., Weitz, C. M., Squyres, S. W., Bridges, N. T., Murchie, S. L., Seelos, F., Seelos, K., Okubo, C. H., , Milazzo, M. P., et al. (2007). A Closer Look at Water-Related Geologic Activity on Mars. Science, 317(5845), 1706-1709. doi:10.1126/science.1143987
• McEwen, A., Eliason, E., Bergstrom, J., Bridges, N., Hansen, C., Delamere, W., Grant, J., Gulick, V., Herkenhoff, K., Keszthelyi, L., kirk, R., Mellon, M., Squyres, S., Thomas, N., & Weitz, C. (2007). Mars reconnaissance orbiter's high resolution imaging science experiment (HiRISE). Journal of Geophysical Research: Planets, 112(5). doi:10.1029/2005je002605
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  The HiRISE camera features a 0.5 m diameter primary mirror, 12 m effective focal length, and a focal plane system that can acquire images containing up to 28 Gb (gigabits) of data in as little as 6 seconds. HiRISE will provide detailed images (0.25 to 1.3 m/pixel) covering ∼1% of the Martian surface during the 2-year Primary Science Phase (PSP) beginning November 2006. Most images will include color data covering 20% of the potential field of view. A top priority is to acquire ∼1000 stereo pairs and apply precision geometric corrections to enable topographic measurements to better than 25 cm vertical precision. We expect to return more than 12 Tb of HiRISE data during the 2-year PSP, and use pixel binning, conversion from 14 to 8 bit values, and a lossless compression system to increase coverage. HiRISE images are acquired via 14 CCD detectors, each with 2 output channels, and with multiple choices for pixel binning and number of Time Delay and Integration lines. HiRISE will support Mars exploration by locating and characterizing past, present, and future landing sites, unsuccessful landing sites, and past and potentially future rover traverses. We will investigate cratering, volcanism, tectonism, hydrology, sedimentary processes, stratigraphy, aeolian processes, mass wasting, landscape evolution, seasonal processes, climate change, spectrophotometry, glacial and periglacial processes, polar geology, and regolith properties. An Internet Web site (HiWeb) will enable anyone in the world to suggest HiRISE targets on Mars and to easily locate, view, and download HiRISE data products. Copyright 2007 by the American Geophysical Union.
• Urquhart, M., & Gulick, V. (2003). Plausibility of the "White Mars" hypothesis based upon the thermal nature of the Martian subsurface. Geophysical Research Letters, 30(12). doi:10.1029/2002gl016158
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  The "White Mars" hypothesis asserts that CO2 gas-driven debris flows were responsible for carving the outflow channels, the valley networks and the gullies on Mars rather than liquid water. This model further asserts that liquid water has been confined to the deep subsurface unable to find egress to erode the surface. We show that the subsurface of Mars, especially when major fluvial features formed, is unlikely to have been as cold as this model suggests and that liquid water would be present much closer to the surface than predicted by "White Mars". The assumptions of the "White Mars" hypothesis regarding globally-averaged crustal heat flow are below most estimates of the current thermal state of the Martian crust, and well below probable values 2 Gyr or more ago. Likewise, the assumed value of crustal thermal conductivity in "White Mars" is inconsistent with the CO2 dominated cryosphere of the model.
• Chapman, M., Smellie, J., Gudmundsson, M., Gulick, V., Jakobsson, S., & Skilling, I. (2001). Study of volcano/ice interactions gains momentum. Eos, 82(21). doi:10.1029/01eo00130
• De Hon, R., Barlow, N., Reagan, M., Bettis, E., Foster, C., Gulick, V., Crumpler, L., Aubele, J., Chapman, M., & Tanaka, K. (2001). Observation of the geology and geomorphology of the 1999 Marsokhod test site. Journal of Geophysical Research: Planets, 106(4). doi:10.1029/1999je001167
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  The Marsokhod rover returned data from six stations that were used to decipher the geomorphology and geology of a region not previously visited by members of the geomorphology field team. Satellite images and simulated descent images provided information about the regional setting. The landing zone was on an alluvial apron flanking a mountain block to the west and a playa surface to the east. Rover color images, infrared spectra analysis of the mountains, and the apron surface provided insight into the rock composition of the nearby mountains. From the return data the geomorphology team interpreted the region to consist of compressionally deformed, ancient marine sediments and igneous rocks exposed by more recent extensional tectonics. Unconsolidated alluvial materials blanket the lower flanks of the mountains. An ancient shoreline cut into alluvial material marks a high stand of water during a past, wetter climate period. Playa sediments floor a present-day, seasonally, dry lake. Observations made by the rover using panoramic and close-up (hand specimens-scale) image data and color scene data confirmed the presence of boulders, cobbles, and fines of various provinces. Rover traverses to sites identified as geologically distinct, such as fan, channel, shoreline, and playa, provided useful clues to the geologic interpretations. Analysis of local rocks was given context only through comparison with distant geologic features. These results demonstrated the importance of a multifaceted approach to site interpretation through comparison of interpretations derived by differing geologic techniques. Copyright 2001 by the American Geophysical Union.
• Gulick, V. (2001). Origin of the valley networks on Mars: A hydrological perspective. Geomorphology, 37(3-4). doi:10.1016/s0169-555x(00)00086-6
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  The geomorphology of the martian valley networks is examined from a hydrological perspective for the compatibility with an origin by rainfall, globally higher heat flow, and localized hydrothermal systems. Comparison of morphology and spatial distribution of valleys on geologic surfaces with terrestrial fluvial valleys suggests that most martian valleys are probably not indicative of a rainfall origin, nor are they indicative of formation by an early global uniformly higher heat flow. In general, valleys are not uniformly distributed within geologic surface materials as are terrestrial fluvial valleys. Valleys tend to form either as isolated systems or in clusters on a geologic surface unit leaving large expanses of the unit virtually untouched by erosion. With the exception of fluvial valleys on some volcanoes, most martian valleys exhibit a sapping morphology and do not appear to have formed along with those that exhibit runoff morphology. In contrast, terrestrial sapping valleys form from and along with runoff valleys. The isolated or clustered distribution of valleys suggests localized water sources were important in drainage development. Persistent groundwater outflow driven by localized, but vigorous hydrothermal circulation associated with magmatism, volcanism, impacts, or tectonism is, however, consistent with valley morphology and distribution. Snowfall from sublimating ice-covered lakes or seas may have provided an atmospheric source of water for the formation of some valleys in regions where the surface is easily eroded and where localized geothermal/hydrothermal activity is sufficient to melt accumulated snowpacks. © 2001 Elsevier Science B.V. All rights reserved.
• Gulick, V., Morris, R., Ruzon, M., & Roush, T. (2001). Autonomous image analyses during the 1999 Marsokhod rover field test. Journal of Geophysical Research: Planets, 106(4). doi:10.1029/1999je001182
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  A Martian rover capable of analyzing images autonomously could traverse greater path lengths and return data with greater scientific content. A more intelligent rover could, for example, automatically select targets of interest (e.g., rocks, layers), return spectral or high-resolution image data of these targets at the same time, remove less interesting or redundant parts of images before transmitting them, and provide compact information or representations of its environment. Three prototype algorithms, a horizon detector, a rock detector, and a layer detector have been developed and tested during the 1999 Marsokhod rover field test in Silver Lake, California. The results are encouraging and demonstrate the potential savings in time as well as the potential increase in the amount of relevant science data returned in each command cycle. Copyright 2001 by the American Geophysical Union.
• Komatsu, G., Gulick, V., & Baker, V. (2001). Valley networks on Venus. Geomorphology, 37(3-4). doi:10.1016/S0169-555X(00)00084-2
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  Valley networks on Venus are classified as rectangular, labyrinthic and pitted, or irregular. The venusian valley networks are structurally controlled, as indicated by the morphological patterns of valley branches, consistency between valley and fracture orientations, and associations with the deformed terrains. The morphologies resemble those of terrestrial and martian sapping valleys. Valley networks on Venus probably formed initially from fracture systems and became enlarged by low viscosity lava sapping processes. Subsurface flow of lava may locally have been assisted by surface flows. The lavas probably moved through permeable media and fractures. Venusian valley networks have a higher degree of network integration than do lunar sinuous rilles, but they are less integrated than martian and terrestrial sapping valleys. The viscosity of valley-forming lavas must have been very low, but was not low enough to exploit the permeable media so extensively as to attain a high degree of network integration. The compositions of these lavas may have been mafic to ultramafic or mafic alkaline. Alternatively, the lavas could have had more exotic compositions, such as carbonatite and sulfur. Valley networks are often associated with corona and corona-like features, which are hypothesized to be the surface expressions of mantle plumes. A plume association could mean that the lavas came from the mantle. © 2001 Elsevier Science B.V. All rights reserved.
• Gulick, V. (1998). Magmatic intrusions and a hydrothermal origin for fluvial valleys on Mars. Journal of Geophysical Research: Planets, 103(8). doi:10.1029/98je01321
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  Numerical models of Martian hydrothermal systems demonstrate that system associated with magmatic intrusions greater than several hundred cubic kilometres can provide sufficient groundwater outflow to form the observed fluvial valleys, if subsurface permeability exceeds about 1.0 darcy. Groundwater outflow increases with increasing intrusion volume and subsurface permeability and is relatively insensitive to intrusion depth and subsurface porosity within the range considered here. Hydrothermally-derived fluids can melt through 1 to 2 km thick ice-rich permafrost layers in several thousand years. Hydrothermal systems thus provide a viable alternative to rainfall for providing surface water for valley formation. This mechanism can form fluvial valleys not only during the postulated early warm, wet climatic epoch, but also during more recent epochs when atmospheric conditions did not favor atmospheric cycling of water. The clustered distribution of the valley networks on a given geologic surface or terrain unit of Mars may also be more compatible with localized, hydrothermally-driven groundwater outflow than regional rainfall. Hydrothermal centers on Mars may have provided appropriate environments for the initiation of life or final oases for the long-term persistence of life.
• Gulick, V., Tyler, D., McKay, C., & Haberle, R. (1997). Episodic ocean-induced CO2greenhouse on Mars: Implications for fluvial valley formation. Icarus, 130(1). doi:10.1006/icar.1997.5802
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  Pulses of CO2injected into the martian atmosphere more recently than 4 Ga can place the atmosphere into a stable, higher pressure, warmer greenhouse state. One to two bar pulses of CO2added to the atmosphere during the past several billion years are sufficient to raise global mean temperatures above 240 or 250 K for tens to hundreds of millions of years, even when accounting for CO2condensation. Over time, the added CO2is lost to carbonates, the atmosphere collapses and returns to its buffered state. A substantial amount of water could be transported during the greenhouse periods from the surface of a frozen body of water created by outflow channel discharges to higher elevations, despite global temperatures well below freezing. This water, precipitated as snow, could ultimately form fluvial valleys if deposition sites are associated with localized heat sources, such as magmatic intrusions or volcanoes. Thus, if outflow channel discharges were accompanied by the release of sufficient quantities of CO2, a limited hydrological cycle could have resulted that would have been capable of producing geomorphic change sufficient for fluvial erosion and valley formation. Glacial or periglacial landforms would also be a consequence of such a mechanism. © 1997 Academic Press.
• Komatsu, G., Baker, V., Gulick, V., & Parker, T. (1993). Venusian Channels and Valleys: Distribution and Volcanological Implications. Icarus, 102(1). doi:10.1006/icar.1993.1029
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  Nearly complete image coverage of Venus by Magellan enabled us to map various venusian channel and valley landforms and to examine their associations with other geological units. Global mapping reveals a nonrandom distribution. The highest total concentration is in the equatorial regions, characterized by highlands, rift and fracture zones, and associated volcanic features. Many channels associated with flow deposits are similar to typical terrestrial lava drainage channels. They are observed to be associated with a wide range of volcanic edifices, such as coronae, shield volcanoes, and rift and fracture zones. One type of channel, similar morphologically to lunar sinuous rilles, is classified as a venusian sinuous rille. Based on the close associations of many venusian sinuous rilles with coronae, we hypothesize that mantle plume or blob volcanism has caused high effusion and sustained lava eruptions essential for sinuous rille formation. Mantle-derived, high-temperature, low-viscosity lava eruptions are responsible for the efficient erosional processes, particularly for thermal erosion that seems to be, at least partially, required for some sinuous rille formation. Many valley networks are observed in highlands and in association with coronae. Fracture systems and source zones for low-viscosity lavas, both key to network formation, were probably concentrated at highlands and coronae. Canali-type channels, which are morphologically unlike other known volcanic channels, are limited to certain plains regions. A wide range of low-viscosity lava types is possible for the channel-forming lava, depending on the formation mechanism. Their lengths exceed the lengths of other common volcanic channel types on Venus, implying a large volume of lava and long duration of the eruption. The close association of canali with plains regions implies that canali formation is probably related to the emplacement of plains. A hypothesized global resurfacing event late in Venusian history may be responsible for canali formation. © 1993 by Academic Press, Inc.
• Gulick, V., & Baker, V. (1990). Origin and evolution of valleys on Martian volcanoes. Journal of Geophysical Research, 95(9). doi:10.1029/jb095ib09p14325
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  Morphological analyses of six Martian volcanoes, Ceraunius Tholus, Hecates Tholus, Alba Patera, Hadriaca Patera, Apollinaris Patera, and Tyrrhena Patera, indicate that fluvial processes were the dominant influence in the initiation and subsequent development of many dissecting valleys. Lava processes and possibly volcanic density flows were also important as valley-forming processes. The presence of anomalously young fluvial valleys on Alba Patera indicates that fluvial valley activity did not entirely cease near the end of late heavy bombardment but rather persisted in isolated regions until mid to late Amazonian. -from Authors
• Gulick, V., & Baker, V. (1989). Fluvial valleys and martian palaeoclimates. Nature, 341(6242). doi:10.1038/341514a0
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  NETWORKS of small fluvial valleys are extensively developed throughout the ancient heavily cratered terrains of Mars. The existence of the valleys has been cited as compelling evidence for a relatively dense primordial atmosphere capable of maintaining an Earth-like hydrological cycle. Theoretical models of early atmospheric evolution describe the maintenance of a dense CO2 atmosphere and a warm, wet climate until the end of the heavy-bombardment phase of impacting. However, the presence of very young, Earth-like fluvial valleys on the northern flank of Alba Patera conflicts with this scenario. Whereas the widespread ancient martian valleys generally have morphologies indicative of sapping erosion by the slow outflow of subsurface water, the local Alba valleys were probably formed by surface-runoff processes. Because subsurface water flow might be maintained by hydro-thermal energy inputs and because surface-runoff valleys developed late in martian history, when planet-wide climatic conditions were presumably similar to the present, it is not necessary to invoke drastically different planet-wide climatic conditions to explain valley development on Mars. The Alba fluvial valleys can be explained by hydrothermal activity or outflow-channel discharges that locally modified the atmosphere inducing precipitation and local overland flow on low-permeability volcanic ash. © 1989 Nature Publishing Group.

Proceedings Publications

• Harrell, M., Gulick, V., & Huang, R. (2022, mar). Analysis of Gullies on the Northern Rim of Nqutu Crater, Mars. In 53rd Lunar and Planetary Science Conference, 2678.
• Huang, R., & Gulick, V. (2022, mar). Comparison of Elevation on Martian Gully Morphology at Crater Gully Sites. In 53rd Lunar and Planetary Science Conference, 2678.
• Cabrol, N., Bishop, J., Cady, S. L., Demergasso, C., Hinman, N., Hoffman, M., Kanik, I., Moersch, J., Noffke, N., Parro, V., Phillips, C., Phillips, M., S{'anchez, G. L., Sobron, P., Summers, D., Warren-Rhodes, K., Wettergreen, D., F{'ernandez-Mart'inez}, M. A., & Gulick, V. (2021, may). "Addressing Strategic Knowledge Gaps in the Search for Biosignatures on Mars". In Bulletin of the American Astronomical Society, 53.
• Cabrol, N., Fenton, L. K., Warren-Rhodes, K., Hines, J., Hinman, N., Moersch, J., Sobron, P., Wettergreen, D. S., Zacny, K., Race, M., Martinez-Frias, J., Paganelli, F., Blank, J., Landis, G., Fairen, A., Andersen, D., Bishop, J., Cartwright, R., Dobrovolskis, A., , Elowitz, M., et al. (2021, may). "BIOMARS: A Foundational High-Resolution Environmental Sensor Array". In Bulletin of the American Astronomical Society, 53.
• Daubar, I., Beyer, R. A., Hamilton, V., McEwen, A., Bardabelias, N., Brooks, S. M., Byrne, P. K., Byrne, S., Calef, I., Castillo-Rogez, J., Diniega, S., Gulick, V. C., Hamilton, C. W., Jha, D., Keresztur, A., Nunn, C., Schenk, P., & Sutton, S. S. (2021, may). "Extended Missions in Planetary Science: Impacts to Science and the Workforce". In Bulletin of the American Astronomical Society, 53.
• Gulick, V., & Glines, N. (2021, mar). "Studies of Martian Gully Systems and Their Potential Paleoenvironmental Settings". In 52nd Lunar and Planetary Science Conference.
• Hargitai, H., & Gulick, V. (2021, jun). "The Map of the Channels East of Olympus Mons". In 2021 Annual Meeting of Planetary Geologic Mappers, 2610.
• Huang, R., Huang, R., Gulick, V., Gulick, V., Glines, N., & Glines, N. (2021, mar). "Slope Analysis of Martian Gullies in Three High-Northern Latitude Craters". In 52nd Lunar and Planetary Science Conference.
• Johnsen, T., & Gulick, V. (2021, mar). "Multimodal Machine Learning with Dual-Band Raman Spectroscopy for Mineral Classification". In 52nd Lunar and Planetary Science Conference.
• Rogers, E., Gulick, V., & Glines, N. (2021, mar). "Understanding Equatorial Gully Erosion on Mars: A Case Study on Krupac Crater". In 52nd Lunar and Planetary Science Conference.
• Glines, N., & Gulick, V. (2020, dec). "Gullies on the Central Peak/Pit of Bamberg Crater". In AGU Fall Meeting Abstracts, 2020.
• Glines, N., & Gulick, V. (2020, mar). "Investigating Potential Thaw or Freeze-Thaw Paleolakes and Channels on the Floor of Lyot Crater, Mars". In 51st Annual Lunar and Planetary Science Conference.
• Huang, R., Gulick, V., & Glines, N. (2020, dec). "Morphologic and Slope Studies of Crater Gullies in the High-Northern Latitudes of Mars.". In AGU Fall Meeting Abstracts, 2020.
• Huang, R., Gulick, V., & Glines, N. (2020, mar). "Shape Analysis of Martian Gullies in Two High-Northern Latitude Craters". In 51st Annual Lunar and Planetary Science Conference.
• Tiscareno, M., Bonaccorsi, R., Bishop, J., Bywaters, K., Cody, A., Caldwell, D., Dalle Ore, C., Farah, W., Gulick, V., Harman, P., Lee, P., Kulpa, J., Marchis, F., Pollak, A., Rudolph, A., Siemion, A., Summers, D., Tarter, J., & Schoultz, S. (2020, dec). "A virtual REU program in Astrobiology and Planetary Science at the SETI Institute". In AGU Fall Meeting Abstracts, 2020.
• Bishop, J., Koeberl, C., Englert, P., Toner, J., Gulick, V., Burton, Z., Gibson, E., & McEwen, A. (2019, dec). "Martian Near-Surface S and Cl Brines in Fractured and Porous Regolith Could Trigger Microscale Soil Collapse and Cause Recurring Slope Lineae". In AGU Fall Meeting Abstracts, 2019.
• Bishop, J., Toner, J., Englert, P., Gulick, V., McEwen, A., Burton, Z., Thomas, M., Gibson, E., & Koeberl, C. (2019, mar). "Salty Solution to Slipping Soils on Martian Slopes". In 50th Annual Lunar and Planetary Science Conference.
• Glines, N., & Gulick, V. (2019, dec). "Potential Freeze-Thaw Paleolakes and Channels on the Floor of Lyot Crater, Mars". In AGU Fall Meeting Abstracts, 2019.
• Gulick, V., & Glines, N. (2019, dec). "Morphologic, Slope, and Volume Studies of Martian Gully Systems:Implications for Paleoenvironmental Settings". In AGU Fall Meeting Abstracts, 2019.
• Gulick, V., & Glines, N. (2019, jul). "Gully Formation on the Central Peak of Lyot Crater, Mars: Implications for a Late Paleo Microclimate". In Ninth International Conference on Mars, 2089.
• Gulick, V., & Glines, N. (2019, sep). "Morphologic, Slope, and Volume Studies of Several Martian Gully Systems". In EPSC-DPS Joint Meeting 2019, 2019.
• Gulick, V., Summers, D. P., & Quinn, R. C. (2019). Mid-IR and Raman Spectroscopy of Perchlorates. In 2019 Astrobiology Science Conference.
• Huang, R., Gulick, V., & Glines, N. (2019, dec). "Analysis of Gully Systems in Two High-Northern Latitude Craters on Mars". In AGU Fall Meeting Abstracts, 2019.
• Johnsen, T., & Gulick, V. (2019, dec). "Artificial Intelligence to Classify Minerals and Rocks with Raman Spectra and Image Analysis". In AGU Fall Meeting Abstracts, 2019.
• Langenkamp, T., Gulick, V., & Glines, N. (2019, mar). "Geomorphic Analysis of Martian Gullies in Western Asimov Crater". In 50th Annual Lunar and Planetary Science Conference.
• Naor, R., Gulick, V. C., & Glines, N. H. (2019, sep). "Subsurface Volume Loss and Collapse due to Surface Infiltration of Osuga Valles' Catastrophic Floods, Mars". In EPSC-DPS Joint Meeting 2019, 2019.
• Glines, N., & Gulick, V. (2018, mar). "Thermokarst Paleolake Assemblages and Channels in Lyot Crater, Mars". In 49th Annual Lunar and Planetary Science Conference.
• Hamid, S., & Gulick, V. (2018, mar). "Geomorphological Analysis of Gullies Along Western Slopes of Palikir Crater". In 49th Annual Lunar and Planetary Science Conference.
• Luu, K., Gulick, V., & Glines, N. (2018, mar). "Gully Formation on the Northwestern Slope of Palikir Crater, Mars". In 49th Annual Lunar and Planetary Science Conference.
• Summers, D., Quinn, R., & Gulick, V. (2018, jul). "Mid-IR Spectroscopy of Perchlorates". In 42nd COSPAR Scientific Assembly, 42.
• Glenn Deardorff, D., & Gulick, V. (2003). Marsoweb: A collaborative web facility for Mars landing site and global data studies. In Proceedings of the SPIE.
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  Marsoweb is a collaborative web environment that has been developed for the Mars research community to better visualize and analyze Mars orbiter data. Its goal is to enable online data discovery by providing an intuitive, interactive interface to data from the Mars Global Surveyor and other orbiters. Recently, it has served a prominent role as a resource center for those involved in landing site selection for the Mars Explorer Rover 2003 missions. In addition to hosting a repository of landing site memoranda and workshop talks, it includes a Java-based interface to a variety of datamaps and images. This interface enables the display and numerical querying of data, and allows data profiles to be rendered from user-drawn cross-sections. High-resolution Mars Orbiter Camera (MOC) images (currently, over 100,000) can be graphically perused; browser-based image processing tools can be used on MOC images of potential landing sites. An automated VRML atlas allows users to construct "flyovers" of their own regions-of-interest in 3D. These capabilities enable Marsoweb to be used for general global data studies, in addition to those specific to landing site selection. As of September 2002, over 70,000 distinct users from NASA, USGS, academia, and the general public have accessed Marsoweb.
• Young, L., Aiken, E., Gulick, V., Mancinelli, R., & Briggs, G. (2002). Rotorcraft as Mars Scouts. In Proceedings of the IEEE Aerospace Conference.
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  A new approach for the robotic exploration of Mars is detailed: the use of small, ultralightweight, autonomous rotary-wing aerial platforms. Missions based on robotic rotorcraft could make excellent candidates for the NASA Mars Scout program. The paper details the work to date and future planning required for the development of such 'Mars rotorcraft'. © 2002 IEEE.