3 May 2023
A small but interesting landslide at Park City in Utah, USA
The Park Record has an interesting story about a small landslide that occurred on a slope in Park City, Utah on 30 April 2023. Recently, I highlighted that there is an expectation of a increased landslide activity in Utah this Spring. The landslide occurred on a slope above a hotel, Marriott’s MountainSide, which was reportedly damaged. This image below, from the Park Record, shows the aftermath of the event:-
The Park Record reports that the landslide is about 30 m long, 20 m wide and 4.5 m deep.
The Google Earth image below shows the site of the landslide in May 2022:-
The hotel is the large building that runs across the lower part of the image, whilst the slope that failed is in the centre of the picture. Note the construction in the upper left quarter, above the slope – this is reportedly the King’s Crown development. The Park Record notes the proximity of the crown of the landslide to the construction work, which is consistent with the debris in the first image above.
The Google Earth image suggests to me that the slope that failed may have suffered previous instability – note the hummocky topography and the apparently steep scarps towards the top of the slope. The timing of the landslide suggests that snowmelt might have played a role, especially given the unusually high volumes of snow that have fallen this winter. The role of human activity is harder to determine – did the works at the top of the slope cause increased likelihood of failure, either by disrupting the drainage or by loading the crown of the landslide? Or did cutting of the toe of the slope remove support for the soil mass? A proper geotechnical investigation is needed with some urgency.