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Zimbelman, J. R.

Publications and source records attributed to Zimbelman, J. R..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2015

Volcanism on Mars

Spacecraft exploration has revealed abundant evidence that Mars possesses some of the most dramatic volcanic landforms found anywhere within the solar system. How did a planet half the size of Earth produce volcanoes like Olympus Mons, which is several times the size of the largest volcanoes on Earth? This question is an example of the kinds of issues currently being investigated as part of the space-age scientific endeavor called "comparative planetology." This chapter summarizes the basic information currently known about volcanism on Mars. The volcanoes on Mars appear to be broadly similar in overall morphology (although, often quite different in scale) to volcanic features on Earth, which suggests that Martian eruptive processes are not significantly different from the volcanic styles and processes on Earth. Martian volcanoes are found on terrains of different age, and Martian volcanic rocks are estimated to comprise more than 50% of the Martian surface. This is in contrast to volcanism on smaller bodies such as Earth's Moon, where volcanic activity was mainly confined to the first half of lunar history (see "Volcanism on the Moon"). Comparative planetology supports the concept that volcanism is the primary mechanism for a planetary body to get rid of its internal heat; smaller bodies tend to lose their internal heat more rapidly than larger bodies (although, Jupiter's moon Io appears to contradict this trend; Io's intense volcanic activity is powered by unique gravitational tidal forces within the Jovian system; see "Volcanism on Io"), so that volcanic activity on Mars would be expected to differ considerably from that found on Earth and the Moon.

Mars↗
NASA NTRS2012

The Origin of Ina: Evidence for Inflated Lava Flows on the Moon

Ina is an enigmatic volcanic feature on the Moon known for its irregularly shaped mounds, the origin of which has been debated since the Apollo Missions. Three main units are observed on the floor of the depression (2.9 km across, < or =64 m deep) located at the summit of a low-shield volcano: irregularly shaped mounds up to 20 m tall, a lower unit 1 to 5 m in relief that surrounds the mounds, and blocky material. Analyses of Lunar Reconnaissance Orbiter Camera images and topography show that features in Ina are morphologically similar to terrestrial inflated lava flows. Comparison of these unusual lunar mounds and possible terrestrial analogs leads us to hypothesize that features in Ina were formed through lava flow inflation processes. While the source of the lava remains unclear, this new model suggests that as the mounds inflated, breakouts along their margins served as sources for surface flows that created the lower morphologic unit. Over time, mass wasting of both morphologic units has exposed fresh surfaces observed in the blocky unit. Ina is different than the terrestrial analogs presented in this study in that the lunar features formed within a depression, no vent sources are observed, and no cracks are observed on the mounds. However, lava flow inflation processes explain many of the morphologic relationships observed in Ina and are proposed to be analogous with inflated lava flows on Earth.

Garry, W. B.↗
NASA NTRS2012

Surface Textures and Features Indicative of Endogenous Growth at the McCartys Flow Field, NM, as an Analog to Martian Volcanic Plains

Basaltic lavas typically form channels or tubes, which are recognized on the Earth and Mars. Although largely unrecognized in the planetary community, terrestrial inflated sheet flows also display morphologies that share many commonalities with lava plains on Mars. The McCartys lava flow field is among the youngest (approx.3000 yrs) basaltic flows in the continental United States. The southwest sections of the flow displays smooth, flat-topped plateaus with irregularly shaped pits and hummocky inter-plateau units that form a polygonal surface. Plateaus are typically elongate in map view, up to 20 m high and display lineations within the glassy crust. Lineated surfaces occasionally display small < 1m diameter lava coils. Lineations are generally straight and parallel each other, sometimes for over 100 meters. The boundaries between plateaus and depressions are also lineated and tilted to angles sometimes approaching vertical. Plateau-parallel cracks, sometimes containing squeeze-ups, mark the boundary between tilted crust and plateau. Some plateau depressions display level floors with hummocky surfaces, while some are bowl shaped with floors covered in broken lava slabs. The lower walls of pits sometimes display lateral, sagged lava wedges. Infrequently, pit floors display the upper portion of a tumulus from an older flow. In some places the surface crust has been disrupted forming a slabby texture. Slabs are typically on the scale of a meter or less across and no less than 7-10 cm thick. The slabs preserve the lineated textures of the undisturbed plateau crust. It appears that this style of terrain represents the emplacement of an extensive sheet that experiences inflation episodes within preferred regions where lateral spreading of the sheet is inhibited, thereby forming plateaus. Rough surfaces represent inflation-related disruption of pahoehoe lava and not a a lava. Depressions are often the result of non-inflation and can be clearly identified by lateral squeeze-outs along the pit walls that form when the rising crust exposes the still liquid core of the sheet. The plains of Tharsis and Elysium, Mars, display many analogous features

Bleacher, Jacob E.↗
NASA NTRS2011

Inflation Features of the Distal Pahoehoe Portion of the 1859 Mauna Loa Flow, Hawaii; Implications for Evaluating Planetary Lava Flows

The 1859 eruption of Mauna Loa, Hawaii, resulted in the longest subaerial lava flow on the Big Island. Detailed descriptions were made of the eruption both from ships and following hikes by groups of observers; the first three weeks of the eruption produced an `a`a flow that reached the ocean, and the following 10 months produced a pahoehoe flow that also eventually reached the ocean. The distal portion of the 1859 pahoehoe flow component includes many distinctive features indicative of flow inflation. Field work was conducted on the distal 1859 pahoehoe flow during 2/09 and 3/10, which allowed us to document several inflation features, in or-der evaluate how well inflated landforms might be detected in remote sensing data of lava flows on other planets.

Zimbelman, J. R.↗
NASA NTRS2010

Geologic Mapping of the Medusae Fossae Formation, Mars, and the Northern Lowland Plains, Venus

This report summarizes the status of mapping projects supported by NASA grant NNX07AP42G, through the Planetary Geology and Geophysics (PGG) program. The PGG grant is focused on 1:2M-scale mapping of portions of the Medusae Fossae Formation (MFF) on Mars. Also described below is the current status of two Venus geologic maps, generated under an earlier PGG mapping grant.

Zimbelman, J. R.↗
NASA NTRS2009

Geologic Mapping of the Medusae Fossae Formation on Mars and the Northern Lowland Plains of Venus

This report summarizes the status of mapping projects supported by NASA grant NNX07AP42G, through the Planetary Geology and Geophysics (PGG) program. The PGG grant is focused on 1:2M-scale mapping of portions of the Medusae Fossae Formation (MFF) on Mars. Also described below is the current status of two Venus geo-logic maps, generated under an earlier PGG mapping grant.

Zimbelman, J. R.↗
NASA NTRS2008

Geologic Mapping of the Medusae Fossae Formation on Mars (MC-8 SE and MC-23 NW) and the Northern Lowlands of Venus (V-16 and V-15)

This report summarizes the status of a mapping project supported by NASA grant NNX07AP42G, funding for which became available on July 18, focusing on the mapping of the Medusae Fossae Formation (MFF) on Mars. The report also briefly discusses the status of maps of Venus and Ascraeus Mons, begun under previous NASA grants but which are still in progress.

Zimbelman, J. R.↗
NASA NTRS2004

Geomorphologic Studies of a Very Long Lava Flow in Tharsis, Mars

CEPS has undertaken an extended study of long lava flows on the terrestrial planets, their location, morphology, and potential modes of emplacement. As part of this ongoing investigation, we have concentrated on a single large flow in Tharsis, with noted similarities to several terrestrial analogs. An impressive series of lava flows emerges from the topographic saddle between Ascraeus and Pavonis Mons. The most prominent of these (hereafter referred to as the 'Saddle Flow') has distinct margins that can be traced for over 480 km in the Viking images, although its exact source cannot be identified. A multimodal approach is utilized in the examination of the Saddle Flow, including image interpretation (VIKING and THEMIS, MOLA topographic analysis and flow profiling, downflow behavior statistical analysis, rheologic modeling, and GIS modeling and integration.

Peitersen, M. N.↗
NASA NTRS2004

Lake Shorelines: Earth Analogs for Hypothesized Martian Coastal Features

The possibility of oceans on Mars has generated a lot of interest in the science community, but conclusive evidence supporting or refuting the ocean hypothesis has remained somewhat elusive. Precise topographic measurements of fresh-appearing shorelines from glacial Lake Lahontan were collected recently in an effort to obtain well-constrained data for comparison with the hypothesized Martian shorelines. This report summarizes the first results of the on-going research project.

Zimbelman, J. R.↗
NASA NTRS2003

Application of THEMIS Data to an Investigation of a Long Lava Flow in the Tharsis Montes Region of Mars

The Tharsis region of Mars has long been known for the numerous lava flows radiating from the Tharsis Montes shield volcanoes. A 480-km-long flow southwest of Ascraeus Mons has been the subject of previous investigations using Viking and MGS data. The new data currently being obtained with the Thermal Emission Imaging System (THEMIS) on the Mars Odyssey spacecraft can shed new light on the volcanology of Martian lava flows, illustrated in this paper by two THEMIS images of the previously studied flow near Ascraeus Mons. The lava flow examined is on the western flank of the topographic saddle between the Ascraeus Mons and Pavonis Mons shield volcanoes. Flow morphology in the dust-covered Tharsis region is revealed in exquisite detail in daytime IR and VIS images from THEMIS, which will aid in documentation and analysis of lava flow features on Mars and improve constraints for volcanic modeling.

Zimbelman, J. R.↗
NASA NTRS2003

The Variability of Transverse Aeolian Ripples in Troughs on Mars

A precursory glance at MGS images of the surface of Mars show an abundance of aeolian transverse ridges. These ridges are located in a variety of geological terrains. Zimbelman and Wilson have separated the small-scale aeolian features of Syrtis Major into six categories: ripples associated with obstacles, ripple bands, ripple fields, ripple patches, isolated ripple patches and ripples associated with dunes. This paper focuses on one of these categories, that of ripple bands which tend to accumulate within linear troughs. As the origin of these features is still being studied (i.e. ripples versus dunes), we refer to them simply as transverse aeolian ridges.

Bourke, M. C.↗
NASA NTRS2003

Geologic Mapping Applications Using THEMIS Data for the Medusae Fossae Formation, Mars

The Medusae Fossae Formation (MFF) is a regionally extensive deposit located along the equator of Mars between roughly 130 and 240 E longitude, the origin of which has stimulated a host of published hypotheses. A volcanic or aeolian origin appear most consistent with Viking and MGS data, but other hypotheses remain viable and new data, as from the Mars Odyssey spacecraft, is likely to stimulate additional hypotheses of origin. NASA is supporting geologic mapping of portions of the MFF deposits, but it is now quite clear that this on-going mapping will need considerable revision as data from the Thermal Emission Imaging System (THEMIS) on Mars Odyssey become available. The daytime IR THEMIS images hold particularly strong potential for providing a new base on which geologic mapping can be carried out, as illustrated by the examples discussed.

Zimbelman, J. R.↗
NASA NTRS2002

Large Ripples on Earth and Mars

Aeolian ripples on Earth with wavelengths greater than 50 cm have distinctive attributes, that should be helpful in interpreting ripple-like features on Mars. Additional information is contained in the original extended abstract.

Williams, S. H.↗
NASA NTRS2001

The Modification of Mars Fluvial Surfaces

The identification of fluvial deposits on Mars is impaired by modifying geological processes. An analysis of surface patterns of superimposed dunes and channels in paleoflood environments in Washington State and Australia can yield information on buried surfaces. Additional information is contained in the original extended abstract.

Bourke, M. C.↗