نتایج جستجو برای: pyroclastic units

تعداد نتایج: 172732  

2011
Mikhail Yu. Zolotov

0019-1035/$ see front matter 2010 Elsevier Inc. A doi:10.1016/j.icarus.2010.12.014 ⇑ Fax: +1 480 965 8102. E-mail address: [email protected] The surface of Mercury contains ancient volcanic features and signs of pyroclastic activity related to unknown magmatic volatiles. Here, the nature of possible magmatic volatiles (H, S, C, Cl, and N) is discussed in the contexts of formation and evolution of...

2014
L. Becerril S. Bartolini R. Sobradelo J. Martí J. M. Morales I. Galindo

Long-term hazard assessment, one of the bastions of risk-mitigation programs, is required for land-use planning and for developing emergency plans. To ensure quality and representative results, long-term volcanic hazard assessment requires several sequential steps to be completed, which include the compilation of geological and volcanological information, the characterisation of past eruptions,...

سالاری, محمدعلی, بومری, محمد , بیابانگرد, حبیب ا... , درگاهی, سارا,

The study area is located in the Kerman province, 10 Km north of Rabor. Geologically, the area is situated in the eastern section of Dehaj-Sarduiyeh belt which is a part of Urumieh-Dokhtar magmatic assemblage. The dykes were intruded in the Eocene pyroclastic rocks and Pliocene sedimentary units. Petrographic studies show that these rocks are andesitic in composition. Mineralogically they are c...

2017
Kevin M. Cannon John F. Mustard Stephen W. Parman Elizabeth C. Sklute M. Darby Dyar Reid F. Cooper

Thirty silicate glasses were synthesized as realistic analogs to those expected to exist on Mars, the Moon, and Mercury. Samples were measured using visible/near-infrared and Mössbauer spectroscopy to determine the effects of varying bulk chemistry, oxygen fugacity, and temperature on spectral properties. For Martian glasses, the fO2 during fusion strongly affects absorption band intensities in...

2003
Lisa R. Gaddis Matthew I. Staid James A. Tyburczy B. Ray Hawke Noah E. Petro

The 5-band Clementine UVVIS data at 100 m/pixel were used to examine the compositions of 75 large and small lunar pyroclastic deposits (LPDs), and these were compared to representative lunar maria and highlands deposits. Results show that the albedo, spectral color, and inferred composition of most LPDs are similar to those of low-titanium, mature lunar maria. These LPDs may have consisted larg...

2009
Katsuaki Koike

Field mapping activity for an active volcano mainly in the Torrid Zone is usually hampered by several problems such as steep terrain and bad atmosphere conditions. In this paper we present a simple solution for such problem by a combination Synthetic Aperture Radar (SAR) and geostatistical methods. By this combination, we could reduce the speckle effect from the SAR data and then estimate rough...

Journal: :Remote Sensing 2017
David B. McAlpin Franz J. Meyer Wenyu Gong James E. Beget Peter W. Webley

Deformation of pyroclastic flow deposits begins almost immediately after emplacement, and continues thereafter for months or years. This study analyzes the extent, volume, thickness, and variability in pyroclastic flow deposits (PFDs) on Augustine Volcano from measuring their deformation rates with interferometric synthetic aperture radar (InSAR). To conduct this analysis, we obtained 48 SAR im...

2007
GREG A. VALENTINE KENNETH H. WOHLETZ SUSAN W. KIEFFER

During the first several minutes of an explosive volcanic eruption, the flow in the column above the vent is unsteady even if the discharge from the vent is steady. At a fixed location in the column, parameters such as temperature and ash content change with time until steady flow conditions are established. For conditions believed to be typical of fountain-forming silicic eruptions of intermed...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی اصفهان - دانشکده ریاضی 1390

the main objective in sampling is to select a sample from a population in order to estimate some unknown population parameter, usually a total or a mean of some interesting variable. a simple way to take a sample of size n is to let all the possible samples have the same probability of being selected. this is called simple random sampling and then all units have the same probability of being ch...

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