President Trump is setting an ambitious timetable for the construction of his promised “big, beautiful border wall.” But aside from potential funding and political complications, geologists and law enforcement officials are pointing to what could be a bigger challenge: the terrain.
Citing everything from bedrock depth to soil chemistry, experts say building a wall spanning the 2,000-mile border will be much tougher than erecting one of Trump’s trademark skyscrapers.
“Earth doesn’t forgive sloppy,” field geologist Mika McKinnon warned in a tweet following Trump’s directive last month to design and construct the wall.
The southern border between the U.S. and Mexico is made up of wetlands, grasslands, desert, rivers, mountains and forests – all of which could pose pitfalls for builders.
Swaths of the area also feature a thick layer of loose sediment – like dirt, sand and soil – on top. Some spots are packed with hydrophilic clay soil, which swells, moves and could destroy the foundation.
“In some places the bedrock will be too deep – you’ll never be able to reach the bedrock in an affordable fashion,” McKinnon told Smithsonian Magazine.
McKinnon says in order to make sure the wall itself doesn’t topple, builders need to survey the land first.
Trump in his executive order called for a study to be completed within 180 days that looks at, among other things, “all geophysical and topographical aspects of the southern border.”
Such planning could entail assembling a team of scientists to test everything from clay particles to loose silt. The Trump administration continues to express confidence it can get the job done — and quickly.