Urban areas such as New Orleans, La. can face many potential hazards, including flooding. Credit: USGS

As a very near sighted child, Michael Wilson studied the ground around his feet and the world close by, including the strata in the cliffs in his neighborhood in Calgary, Canada, he says. Wilson remembers noticing a volcanic ash layer at age 7 and wondering what it was.

“To me, the city has always been a place of wondrous geological discoveries,” said Wilson, who recently retired as chair of the Department of Earth and Environmental Sciences at Douglas College, British Columbia (BC). Observing that other people “imprint” different things, he told Eos, “I’m the little duckling that’s following around after urban geology because that’s the way I have always been.”

Although an interest in urban geology came naturally to Wilson, its importance includes the opportunity to apply geological understandings to help society, he said. With more than 50% of the global population living in cities, the study of geology in urban areas—and how that geology affects people—needs to be revitalized broadly to help with geological hazard mitigation and to provide other societal benefits, he noted. Wilson co-led a 22 October session on urban geology at this year’s annual meeting of the Geological Society of America (GSA) in Vancouver, Canada.

The Value of Urban Geology

Urban geology studies, which date to at least the mid-1800s, can provide “a surprising amount of geological information,” according to Wilson and session co-leader, Lionel Jackson, who is an adjunct professor in the Department of Earth Sciences at Simon Fraser University, BC, and emeritus scientist with the Geological Society of Canada.

Wilson and Jackson—who discussed the need for ongoing urban geological surveys—­said that although many geologists prefer to do research in wild or open spaces because there is less development disturbance, the study of urban geology is critically important to benefit society in a number of areas. It can help residents understand structural geology, hydrology, geochemistry, seismology, volcanology and other concerns, they said.

However, urban geology studies also offer their own challenges, Wilson and Jackson explained. Among those challenges is that some sites may only be available for temporary viewing, perhaps for just a few days before construction progresses and the excavated strata is re-covered.

“The city provides a very active environment in which there is constant disturbance, which is actually revealing geological deposits,” Wilson told Eos. If scientists can quickly mobilize to visit these sites, “we can actually accumulate a lot of information. The trouble is that temporary exposures pop up when we least expect them.”

Studying urban geology requires a slightly different outlook, Wilson continued. “If your interest is in geological processes and documenting large-scale phenomena, then you are likely to want to go away from the city so that you can ‘see things more clearly.’ It’s understandable. A lot of geologists would be interested in the general processes of geology and getting a good look at things.”

He said that the counterargument is that studying urban geology is a key way to explore municipal issues involved with urban expansion, resource allocation, and hazard awareness where most people live. “You’ve got a growing population in the urban area. It is on a geological substrate,” he commented.

Geology is involved “in everything we do in one way or another. Most of the materials that we are using, that we are handling, are geological materials,” Wilson said. However, “people are unaware of the extent to which geology is influencing their daily lives.” He said, for instance, that many people think that natural hazards, such volcanic eruptions, are things of the past or that society has a foolproof way of handling potential flood problems by building dams and taking other measures. Awareness of urban geology can help people avoid such misconceptions and deal with potential hazards more effectively, he added.

A Shared Sense of Place

In addition, Wilson said that urban areas can help foster a shared sense of place for people from diverse backgrounds. “They can share attachment to a place, and of course that means that they share an interest in the environment, and the geological environment is an important part of that,” he said, adding that urban areas can unify a number of different themes in geology.

“People go and stand at the Grand Canyon and say, ‘Wow, it just all comes together now. I can see unconformities, I can see erosion, I can see deposition, all this stuff,’” Wilson said. “What would be wonderful is if people could then look at the city and have that same feeling, because there really is that kind of information here. It’s just that there is, from an analytical standpoint, a lot of noise in a city. But it’s kind of interesting noise in its own way.”

Geological Mapping in Cities

The GSA session included a number of presentations, including one on mapping the urban geology of metropolitan Detroit, Mich., by Daniel Rogers, director of environmental affairs at Amsted Industries, Inc., in Chicago, Ill. Although Detroit may not have geohazard risks from volcanoes, for instance, some of Rogers’s efforts have involved studying geohazard risks from a legacy of industrialization and contamination—­including toxicity, mobility, and persistence—in the metropolitan area.

Rogers said that undertaking urban geology can be challenging because outcrops might be temporary, field work could be dangerous because of traffic and other problems, and mapping can be expensive and time-­consuming. However, he emphasized that urban geological mapping “is a fundamental tool for the protection of human health and the environment.” As such, his work involves integrating geology into urban planning because it “is an element to create sustainable human habitation on Earth,” he said. “We should understand the geology of urban regions much better than in national parks because this is where we live and this is where we have the most contact with the natural world.”

Another scientist at the GSA session, David Boon, deputy head for Wales and engineering geologist for the British Geological Survey (BGS), provided a presentation on a stakeholder-led approach to setting future research priorities for the BGS urban geology program in Wales. Boon told Eos that BGS has been doing applied geoscience research in urban areas for decades, “and this work has supported regeneration of many towns and cities across the UK.”

BGS’s City Region GeoScience in Wales program, which began in April 2012 and will run for another 4−5 years, included a series of stakeholder engagement workshops that Boon said have informed and shaped the program’s urban research strategy and have helped focus resources toward dealing with challenges such as fuel poverty, housing, sustainable drainage systems, and renewable energy.

“In Wales, we have been left with an enormous industrial legacy, with widespread anthropogenic modification of the ground from past coal mining and heavy industry and contaminated land issues. To add to this, we suffer from ground instability issues brought about by former mining activities and slope instability in former glacial valleys. Through the City Region Geoscience program, we are now more closely connected with our main stakeholders in Wales, particularly planning authorities, government, and industry,” Boon told Eos.

He added, “The program is already having a positive effect, and partnership working has improved provision of geological information and research in urban areas in Wales, and is directly supporting those tasked with development, regeneration, and environmental regulation both within our city regions and beyond our borders.” He said the next steps include launching a subsurface knowledge exchange network in Wales.

Economic Benefits of Urban Geology

Wilson and Jackson noted that there has been an impetus to focus on urban geology in Canada, the United States, and many other countries and that the interest is there to do so but that the funding for some of the work has been cut. Jackson said these cuts are unfortunate because a focus on urban geology not only can help to protect people by providing information about geological hazards and other issues related to public health and the environment, but can also save money.

“If you prevent a disaster by identifying a natural hazard and development happens somewhere else as a result, you’re never going to see that” show up on the ledger books, he said. However, the costs of natural disasters often can be very high, so averting disasters by implementing insights from studies of urban geology is well worth doing, he said.

Some major issues will highlight the need for more focus on urban geology, Jackson said. “Things like the impact of global change, where it impacts cities—that is probably where the rubber meets the road right now, particularly these things like sea level rise and extreme weather events and so on,” he said. “Where we have the intersection between [daily life and] big issues like climate change—that’s where I think urban geology concerns are coming to light now.”

Randy Showstack, Staff Writer

© 2014. American Geophysical Union. All rights reserved.

© 2014. American Geophysical Union. All rights reserved.