Evidence for glaciation in Elysium

Evidence for the existence of permafrost and the surface modification due to frost effects and the presence of ice on Mars dates from early observations. Later analysis of the Viking Orbiter imagery produced evidence suggesting the former presence of ice sheets that could have played a part in shaping the surface of Mars. Similarities were pointed out between a number of streamlined Martian channel features and similar streamlined landforms created by Antarctic ice sheet movement. A study of Viking Orbiter imagery of Granicus Valles and the surrounding terrain in Elysium has produced further evidence of glaciation on Mars. Volcanism has played an important role in developing the landscapes of the Elysium region. A possible explanation is that subsidence occurred during formation of the Martian moberg ridges due to the melting of ground ice near the eruption area while at a distance most of the ground ice in the permafrost is still present and the original elevation was preserved. Meltwater during and following eruptions might be suddenly released during subglacial volcanism into Granicus Valles in one case and into Hrad Valles in the other. Fluvial erosion thus could have played a role in shaping both

Evidence for glaciation in Elysium

It is suggested that certain landforms in the Elysium region of Mars provide strong evidence for glaciation. Landscapes related to subglacial volcanism suggest that ice was a primary agent in the development of Elysium

Temperature Fluctuations Which Accompany Soil-Water Movement

This item is part of the Arizona Land and People (formerly Progressive Agriculture in Arizona) archive. It was digitized from a physical copy provided by the College of Agriculture and Life Sciences at The University of Arizona. For more information about this periodical, please email CALS Publications at [email protected]

Application of the LANDSAT Data Collection System in Alaska

International Telemetering Conference Proceedings / October 14-16, 1975 / Sheraton Inn, Silver Spring, MarylandLANDSAT data collection platforms have been interfaced with a variety of environmental and water quality sensors to test performance, reliability and versatility of the LANDSAT data collection system. Signal conditioning interfaces were required for sensors selected to measure: ground, soil and air temperatures; wind passage and speed; snow accumulation and ablation; pore water pressures; salinity; pH; dissolved oxygen; and water stage. System performance was found to be excellent; system reliability was high. Considering technical aspects only, exploitation of this satellite system for automated environmental and water quality data collection is hindered most by the relatively immature state of sensor and interface development. Notwithstanding, well prepared, two man field parties had no difficulty in deploying DCPs with their associated antennae and sensor subsystems in remote subarctic locations. Environmental data acquired at the various sites are being used in the assessment of the environmental impacts associated with the proposed construction of two hydropower dams on the Susitna River in interior Alaska, on the effects of impoundments over permafrost, and in assessing the effects associated with the construction and operation of the trans-Alaska pipeline.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

PLANETARY SOIL WATER ANALYZER (PSWA) PROTOTYPE

International Telemetering Conference Proceedings / September 28-30, 1982 / Sheraton Harbor Island Hotel and Convention Center, San Diego, CaliforniaA microprocessor-based differential scanning calorimeter is being designed for eventual use in planetary soil water analysis. The uniqueness of this effort is in the use of the microprocessor as an integral section of the system control loops, instead of as merely an auxilary processor of output data. The use of differential scanning calorimetry is advantageous in determining water content of soil samples. The basic idea is to use two matched ovens, one with a soil sample included. The average temperature of the ovens is forced to track a desired programmed temperature (normally a slow ramp) with one control loop, while a second control loop forces the oven temperatures to be equal, even during a transition. The power necessary to keep the temperatures equal is monitored, containing information as to the transition energy, and thus the water content at programmed water transition temperatures. This approach uses the microprocessor to close both of the loops, taking oven sensor temperatures as an input, and providing power duty cycles as outputs. In actuality, two microprocessors are used - a slave to accumulate and process sensor information, and a master to generate the loop control, output data control, and temperature program control. The PSWA performance is compared to a state-of-the-art commercial instrument using analog loop control. The major advantage of the microprocessor loop control utilized in the PSWA is the capability of remote operation, including remote alignment and adjustment. Further advantages include accommodation of oven changes with software reprogramming, a flexible single oven capability, correction for system nonlinearities using software, and auto gain and auto zero control for the sensor circuitry. The analog loop control approach has somewhat better sensitivity, resolution, and noise performance. The current phase of the development of the PSWA is a feasibility study and circuit design, performed for the Planetary Geology Program Office, NASA Headquarters. The next developmental phases would include breadboarding, software design, testing, and evaluation. In conclusion, this instrument is a significant advance in the state-of-the-art for automatic water measurements, and will be of great value in further planetary exploration.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection