People

Vicki Hansen is a structural geologist/tectonisist with interests in large scale tectonic processes of planetary bodies. Her regional field areas on Earth include: the western U.S., Yukon, Alaska, Arizona, and Antarctica. Over the last 10-15 years she and her students have concentrated on mapping large regions of Venus, commonly with emphasis on tectonic and magmatic processes. Their goal is to interpret geologic relations at all scales, and decipher local, regional, and global scale geological histories in order to understand Venus' evolution and dynamic processes through time. Specific topics on Venus include: crustal plateau formation and implications for Venus evolution, deformation belt formation, coronae evolution, circular low formation, Venus resurfacing (evidence does NOT support catastrophic resurfacing of Venus contrary to popular views), lowland processes, and tessera-terrain evolution. Hansen and her students have been involved in 1:5 million scale mapping of eight VMaps (30°x25°) for publication through the USGS, and they have just begun 1:10 million scale mapping of two quadrangles (each 120° x 57°).

I am researching the formation of Artemis, the largest known circular surface structure in the solar system. Artemis is centered roughly at 34°S, 132°E on Venus and measures approximately 2600 km in diameter, that’s the distance from Duluth to Los Angeles! The most prominent feature is a ~1 km deep trough with a paired ridge around its perimeter. One puzzling thing about Artemis is that it contains at least five ~300 km diameter circular structures, known as corona. I will be creating detailed geologic maps of the five internal corona based on radar imagery and remote sensing data from the NASA Magellan mission to understand how each corona developed and how they relate to the trough. Several mechanisms have been proposed for forming Artemis, including large scale subduction, a deep mantle plume, and even a meteorite impact. My work will help determine which of the proposed mechanisms are plausible and could lead to refinements of these mechanisms or even a whole new idea. I am excited to see how this research pans out because it requires some unique thinking and highlights some of the differences between processes on Earth and Venus. Please feel free to contact me about Artemis at bann0036@d.umn.edu.

Broadly, my current research addresses volcanic processes in Venus’ plains regions. Questions I am addressing include: a) what styles of volcanism occur in the plains regions? b) how is volcanic material emplaced in these regions? and c) How do Venus’ extreme surface conditions compared with Earth (~720 K, ~100 bars surface pressure, CO 2-rich atmosphere) influence volcanic processes? To help answer these questions, I am geologically mapping a 25° x 30° quadrangle (the Greenaway quadrangle, V-24, which extends from 0°-25° N and 120°-150° E, an area of ~8.4x10^6 km^2 that would easily fit the continent of Australia !) that includes a representative portion of the plains. My results thus far suggest that, at lest locally, volcanism is mostly attributed to small shield volcanoes (or shields, for short). Shields are circular to quasi-circular features that are cone, flat-topped, dome, or shield shaped, ~1-20 km in diameter and generally <<1 km in height. During my mapping I have become interested in channels, which very broadly resemble terrestrial fluvial systems and are apparently very abundant in Venus’ plains. What do they represent? How do they form? I am beginning to address mechanisms of channel formation through a combination of descriptive and numerical techniques. Questions? Comments? Want to know more? Feel free to email me! lang0604@tc.umn.edu

Kelly McDaniel hails from New Jersey. She came to UMD via Virginia Polytechnic Institute where she completed a Bachelor's in Geology. At UMD she whisked herself off to Venus to examine a particular 'flavor' of coronae that we call 'circular lows'. So called because these 60-370 km features form circular depressions. Kelly constructed detailed geologic maps of about five circular lows in order to unravel their respective geologic histories, with the aim to understand how they formed. Notable circular lows lack radial fractures, and they affect their surroundings in a cookie-cutter like fashion. The data are consistent with circular low formation via impact event on tessera terrain, rather than formation by diapirs-a widely held view prior to Kelly's mapping. Kelly is finishing up her degree and headed back to New Jersey to spend time with family and to begin a program in forensics.