The critical importance of natural resources to Alaska gives the state’s Division of Geologic and Geophysical Surveys a particularly crucial role in researching and making available geologic and geophysical information. By working outside the constraints of commercial confidentiality the division provides a wealth of information that can underpin private research and avoid some duplication of research effort.
At a joint meeting of the Alaska Geological Society and the Geophysical Society of Alaska, DGGS Acting Director Bob Swenson talked about the division’s various work programs. Swenson characterized the DGGS mission as determining Alaska’s natural resource potential and evaluating geologic hazards.
A program of detailed geologic mapping, particularly at a scale of one inch to one mile, continues to form a cornerstone of the division’s activities, Swenson said. Despite the relatively short field season in the Alaska summer, DGGS geologists regularly map large areas of territory, particularly in regions with mineral or energy resource interest. In 2006, for example, the division mapped more than 850 square miles, Swenson said.
“That’s a lot of ground to cover in one summer,” Swenson said.
North Slope a major focus
A major focus of the mapping has been the prolific oil and gas province of the North Slope. Over a period of several years a DGGS-led team of geologists has worked its way across a swathe of land on the north side of the Brooks Range, where good rock exposures provide valuable insights into the geology of rock strata buried deep beneath the ground under the slope. The team is now filling in some remaining gaps in its coverage to the north of the Brooks Range, prior to linking its findings there with the subsurface geology of the Colville basin to the north, to gain insights into basin geometry and history (the Colville basin lies under much of the North Slope and contains huge thicknesses of sediment with excellent petroleum potential).
“We’ll be starting to look into the Colville basin proper and taking that outcrop data that we’ve gathered in the foothills region and moving those models out into the basin,” Swenson said. “We’re trying to find seismic data sets that we can use to carry the outcrop data into the basin proper.”
Bristol Bay and Cook Inlet under way
A DGGS-led team has almost completed a multi-year program of research into the geology of the Bristol Bay region, in support of state areawide oil and gas lease sales on the Alaska Peninsula. Swenson said that although the rock exposures in the region as a whole aren’t especially good, the team has made some very interesting findings about the regional geology.
“There’s some cutting-edge work being done by these guys,” Swenson said. “I think it’s very, very important in the overall (geologic) history of south Alaska.”
And DGGS has initiated a similar five-year research program in Cook Inlet. Because of the very tight natural gas supply situation from the Cook Inlet basin, the DGGS team will focus initially on gas exploration plays in the Tertiary section of the basin. With many of the big Cook Inlet geologic structures already having been drilled, DGGS is taking a particular interest in the resource potential of the more subtle stratigraphic plays.
“One of the things that we’re going to be doing is taking a look at the basin-edge geometries and try to understand what facies … may be available for the exploration companies to go out and search for,” Swenson said.
DGGS also wants to investigate the petroleum potential of the Mesozoic strata — the older rocks that lie underneath the Tertiary rocks which contain all of the existing Cook Inlet oil and gas fields.
“The exploration in the Mesozoic is hardly in its primary phase, let alone in the secondary or tertiary phase,” Swenson said.
Volcanoes monitored
DGGS participates with the U.S. Geological Survey and the University of Fairbanks in the Alaska Volcano Observatory, a program to monitor and study Alaska’s hazardous volcanoes; to predict and record eruptive activity; and to mitigate volcanic hazards to life and property.
In particular, Alaska’s many active volcanoes pose a hazard for airlines. And there is general interest in volcanic eruptions — the eruption of Augustine Volcano in Cook Inlet in 2006 triggered 19.7 million hits on the Alaska Volcano Observatory Web site, Swenson said.
Research into the chemistry of the eruptive material from volcanoes in various part of Alaska is providing some puzzling evidence about deep underground movements in the Earth’s crust. The chemistry indicates that volcanism in the northern part of the Alaska Range relates to volcanic activity along the Aleutian island arc. But volcanism in the Wrangells, on the eastern side of Alaska, appears unrelated to that activity. Geologists are still trying to understand that disconnect, Swenson said.
Mineral resources
Alaska is a strategic U.S. source of non-fuel minerals. A big increase in mineral exploration expenditure in recent years reflects high commodity prices and the resource potential of the state. And the majority of current mineral exploration is occurring on state land, Swenson said.
As part of its minerals program, DGGS has completed some detailed geologic mapping in the Nome area and has been conducting an extensive program of airborne geophysical surveying. The state is using helicopters to acquire especially detailed geophysical information and has already published high-resolution data covering more than 5,400 square miles, Swenson said.
DGGS has also flown an aeromagnetic survey along the proposed corridor for a North Slope gas export pipeline. That survey will help locate possible hazards, such as geologic faults. The results of the airborne survey now require verification and assessment on the ground.
“We’ll be out in the field this summer starting the ground work,” Swenson said.
Web-based information
Swenson feels particularly proud of DGGS initiatives to make information available over the Internet. The DGGS Web site has become the poster child for several state surveys, he said.
“All of the great geology in the world is not going to matter if you don’t get that data in an easily accessible, user-friendly format,” Swenson said. “… We want this data to be able to get out into everybody’s hands that needs it.”
The division has seen a huge increase in activity on its Web site — people downloaded more than 200,000 publications, including maps and reports, during 2006, Swenson said.
Rural energy options being compiled
A major new DGGS program to compile energy options for rural Alaska communities is addressing the high cost of energy in rural Alaska. The idea is to make all available data about potential energy sources accessible through a computer-based map system. Each village will be able to look at possible local energy options, including coal, geothermal energy, hydropower and wind energy.
“They will have the data readily available to make reasonable plans for the future on their energy sources,” Swenson said.
And DGGS is also going to assess the geothermal potential of different parts of Alaska. New technologies are enabling viable electricity generation from geothermal sources at relatively low temperatures — mapping of geothermal gradients across different regions could enable the identification of locations where viable geothermal power generation is possible.
The DGGS geothermal initiative will start on the North Slope.
“We’re going through all the well data and we’re going to put together a … geothermal gradient map of the North Slope,” Swenson said. As time and money allow, the division hopes to extend the initiative across the whole state, he said.
DGGS has also been taking an interest in gas hydrates, although the division is not involved in a current government-industry project to assess the viability of gas hydrate development on the North Slope.
Geologic Materials Center
DGGS also manages the Alaska Geologic Materials Center, a facility that contains an extensive collection of rock samples; well core and cutting samples; and microscope slides. The collection, a collaborative venture with other government agencies and private industry, enables easy access to material from wells and remote locations for anyone investigating Alaska geology.
But the collection has outgrown the center’s current facility in Eagle River. And the facility consists of a series of scattered buildings and storage containers that fall short of current design standards for earthquake protection and lack adequate firewater storage. DGGS plans to move the facility to a new location in Eagle River.
“I think it’s a travesty. Having a state that has this type of revenue generated from the development of its resources with a facility … in that kind of shape is unbelievable to me,” Swenson said. “We’re working pretty hard to try to change that.”
DGGS has completed a scoping study for the new facility and is seeking both state and federal funding, Swenson said.
“We do need the support of industry,” Swenson said.
