E Arthur Bettis

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Sangiran (Solo Basin, Central Java, Indonesia) is the singular Homo erectus fossil locale for Early Pleistocene Southeast Asia. Sangiran is the source for more than 80 specimens in deposits with (40)Ar/(39)Ar ages of 1.51-0.9 Ma. In April 2001, we recovered a H. erectus left maxilla fragment (preserving P(3)- M(2)) from the Sangiran site of Bapang. The find(More)
Pollen analysis of pond deposits in the upper reaches of a stream from northeastern Iowa, an area beyond the last glacial margin, provides a nearly complete record of vegetational changes during the last 12.5 thousand years. Sixty-one radiocarbon dates provide good chronological control. Spruce forest was replaced by deciduous forest before 9.1 thousand(More)
Investigating the impact of variations in particle size on heat flow from chaparral fires into soils using a laboratory based wildfire simulator. ABSTRACT It has been well established that under certain circumstances wildfire is capable of producing water repellent or hydrophobic soils. Hydrophobic soils can dramatically alter runoff and erosion processes(More)
The use of multi-channel ground penetrating radar and stream monitoring to investigate the seasonal evolution of englacial and subglacial drainage aystems at the terminus of Exit Glacier, Alaska." PhD (Doctor of Philosophy) thesis, and feedback throughout this process. I am very grateful for the comments and assistance that they provided while developing my(More)
ii ACKNOWLEDGMENTS Special thanks to my adviser Art Bettis; to Adam Ward for assistance with data collection and analysis methods, and for providing edits; to Frank Weirich for his help with my thermocouple array; to Matt Hill for lending me laboratory space to perform my infiltration rate tests; to Trina Roberts and the Natural History Museum Staff for(More)
investigation of the stone zone and loamy mantle on the Iowan surface. ii ACKNOWLEDGEMENTS This master's thesis would not have been possible without the help and support of countless individuals. Firstly and foremost, I thank my advisor, Art Bettis. Without him taking me on as a student and guiding me through this process I wouldn't be here today. I also(More)
ii ABSTRACT To replenish and restore sandbars and thus preserve aquatic and riparian habitats along the Colorado River, four high-flow controlled floods were conducted as part of the Glen Canyon Dam Adaptive Management Program. While studies of the most recent flood research on pre-and post-dam sediment-transport has yielded insights into the process of(More)