The sensors, wirelessly connected, were placed in basements, parking garages and tunnels and monitored the temperature in those environments. One was the Chicago Loop, marked by buildings and underground railway tunnels, and the other was Grant Park, a green space. Rotta Loria and his team installed a network of temperature sensors over and below the ground at two locations in Chicago. As the ground warms up over time, it approaches a thermal saturation state.” “Heat in the subsurface partly derives from the one at the surface of cities, but mostly comes from heat sources including building basements, parking garages, tunnels, sewage networks, and district heating lines. This phenomenon yields so-called surface or meteorological urban heat islands,” Rotta Loria said.
Heat at the surface of cities mostly derives from the fact that construction materials absorb heat from solar radiation and anthropogenic activity, releasing such heat at night in the atmosphere. “The amounts of heat characterising the surface and subsurface of cities differ because they originate from different causes. The phenomenon of underground climate change, in fact, is widely described as underground heat islands. This is in addition to heat that diffuses into the ground from the atmosphere. A heat island occurs in a city when it experiences much higher temperatures than surrounding areas that are less urbanised, a result of the different amounts of heat absorbed by various surfaces in the two areas.īuildings and infrastructure overground, and transport systems underground, are releasing massive amounts of heat continuously into the ground. The phenomenon is somewhat similar to the urban heat island effect. In 2020, the Universities of Cambridge and California, Berkeley, in partnership with the British Geological Survey, launched a project to model and monitor urban underground climate change. While the new study is possibly the first to look at ground deformation as a result of temperature variations, underground climate change itself has been recognised as a hazard for some time now.
Older cities experience a more intense underground climate change,” study author Alessandro Rotta Loria, an assistant professor of civil and environmental engineering at Northwestern University, said in an email interview. “Underground climate change characterises, at least to some extent, all urban areas worldwide.
There is also an ecological impact, such as contamination of groundwater. The study, published in the journal Nature Communications Biology, flags concerns about the impact of underground climate change on civil infrastructure and also about health earlier studies have linked extreme air temperatures underground to heat-induced diseases. The ground beneath Chicago is getting deformed, or shifting, either moving upwards due to the due to the expansion of some materials (such as soft clay) or sinking due to the contraction of other materials (such as hard clay and sand). But what of the impact underground? A study undertaken in Chicago, with potentially global implications, measured underground temperature variations over time and simulated its impact. Research on climate change has mostly focused on the impact on the atmosphere.
0 kommentar(er)
