GIP Staff

Meet our dedicated Staff and Board

Our Staff and Board members have many decades of combined background in geoscientific and engineering endeavors, with practical experience in nearly every realm of geology and related construction and technology industries. We have worked in mineral and energy exploration, mining geology, hazard mapping and abatement, geochemical and stratigraphic studies, field and structural geology, remote sensing and engineering applications. Together, we have worked in nearly every state of the union as well as a number of countries in Europe and South America. We share a passion to apply our skills for the betterment of mankind and our planet, as well as an ability to work in challenging situations. We welcome difficult problems that demand creative solutions.


Greg Wessel

Gregory R. Wessel, Founder and President

Dr. Wessel holds degrees in Geology from Colorado School of Mines (PhD) and the University of Missouri-Rolla (BSc and MSc; now called the Missouri University of Science and Technology). He is also licensed in the State of Washington as an Engineering Geologist and currently sits on the State’s Geologist Licensing Board. Dr. Wessel has over 35 years of experience in metals and industrial minerals exploration, geologic hazard abatement and environmental restoration, geotechnical applications and mapping of geologic hazards, the development of agricultural minerals (sulfur and potash) in Texas, Poland, Ukraine, and Russia, and the recovery of magnesium salts (for metal production) in Russia. He has specialized in geologic mapping and structural evaluations, and has mapped large areas of the southwestern United States and the Altiplano of Bolivia, using aerial photography and extensive field work. Dr. Wessel has authored or co-authored over 20 articles and abstracts, including a number of maps available from the Washington Geological Survey, the Texas Bureau of Economic Geology, and a widely used educational chart available from the Geological Society of America entitled The Geology of Plate Tectonics.

Jeffrey K. Greenberg, Vice President

Dr. Greenberg recently retired as Professor of Geology from Wheaton College (Illinois), where from 1986 to 2018 he taught classes in physical, historical, environmental, structural and field geology, petrology, geochemistry, and geophysics.  Dr. Greenberg received his PhD in Geology in 1978 from the University of North Carolina and his MS in 1975 from the University of Kentucky. He received his BS in Geology from Florida State University in 1973. Jeff has authored numerous publications, including geologic and geophysical maps of parts of Kentucky and Wisconsin, field trip guidebooks, and articles on Precambrian geology, igneous petrology, and most recently religious faith as a motivation in using geosciences to develop a sustainable future.  He is a respected authority on geophilanthropy, both in general and as applied by him and his students in a variety of service projects in Europe and Africa. Dr. Greenberg has organized student missions projects (typically applying geoscience and engineering to service the public good) in South Africa, Tanzania, Kosovo, and Haiti, and served as the Human Needs and Global Resources advisor at Wheaton for a number of nations in the developing world. His research interests range from the application of appropriate technology in community development in impoverished areas to the tectonics of the southern Appalachians.

Board of Directors

Eric Tilman

J. Erik Tilman, Board Chairman

Mr. Tilman holds a BSc in Mechanical Engineering from the University of Missouri-Rolla (now called the Missouri University of Science and Technology). He has 30 years of experience with design and manufacturing in the electronics industry, including a long record with Hewlett Packard Corporation in Loveland, Colorado and Lake Stevens, Washington, and he recently retired from a position as a mechanical engineer for The Boeing Company where he designed components of commercial aircraft. Mr. Tilman is also on the Board of Directors of the Centennial Trail Coalition of Snohomish County, a non-profit organization that assists Snohomish County Parks by advocating for and promoting long distance recreation trails for pedestrians, bicyclists, and equestrians.

John Bethel

John Bethel

Mr. Bethel holds degrees in Geology (BS) and Forest Soils (MS) from the University of Washington, and he is a Licensed Engineering Geologist in the State of Washington. Recently retired from King County’s Department of Natural Resources and Parks, he has 30 years of experience providing geomorphic and geotechnical input for flood control and river enhancement projects, conducting channel migration studies on King County’s rivers, and studying and mapping landslide hazards along a number of river corridors. Mr. Bethel has also provided geologic characterizations in support of watershed planning efforts, contributed to the development of county policy, ordinances, and rules (as they relate to geologic issues), and addressed geologic issues as part of the building permit review process, including through the Comprehensive Plan, the Surface Water Design Manual, and the Sensitive Areas Ordinance. Prior to his work for King County, Mr. Bethel was an engineering geologist for Earth Consultants in Bellevue, Washington, where he specialized in geotechnical site evaluations, slope stability, and construction-related issues. He was also a geologist/field assistant with the U. S. Geological Survey where he provided geohydrologic support for a drilling program in Island County, Washington, and mapped glacial geology in the Cowlitz River valley. Mr. Bethel has also co-authored geologic maps with the Washington Geological Survey, assisting their efforts in eastern King County for several years, and has appeared at public forums and on television and radio as a representative of the county and expert in landslide studies, river migration, and flood control.

Gabriela Perlingeiro Knesel

Dr. Knesel holds degrees in Geology from The University of Queensland (PhD) in Australia and University of São Paulo (BSc) in Brazil, as well as an MBA in Finance from Rome Business School in Italy. She has over 13 years of experience in earth sciences, particularly in the areas of geochemistry, geochronology and petrology, and has conducted fieldwork on four continents. Dr. Knesel works for the Lhoist Group, currently managing the overall mine plan of an 8.5 Mt mine in Texas, following posts within Lhoist’s Global R&D and North American Mining & Exploration teams. She represented Australia as part of the YES Network Leadership Team until she moved to Belgium in 2013, and was the lead organizer of the 2nd World YES Congress, held within the prestigious 34th International Geological Congress in Brisbane in 2012 (with 6000+ attendees). She is a supporter and advocate for women in the mining and metals industry.

Nate Wessel

Nathaniel G. Wessel

Mr. Wessel holds a BSc in Computer Science and a BSc in Psychology from Colorado State University. He is currently a Software Development Engineer with Amazon, where he implements predictive analytics and machine-learning algorithms in order to ensure long-term network reliability. In those moments when he is not working, he can be found backpacking, riding his dirt bike, or being tackled by his dogs. Mr. Wessel is well traveled and exceptionally versed in internet applications to marketing and development. He has also worked with a number of Colorado companies to maintain and upgrade their corporate computer systems, provided customer support for a variety of platforms and mobile devices, and worked with other scientists and engineers to develop new products for biological applications.