An Oceanside Elementary School is Grappling With a Sinkhole Mystery

The start of fall semester at Garrison Elementary School in Oceanside may end up being delayed if officials can’t get to the bottom of a sinkhole problem affecting the campus.

Two dolines have erupted on school grounds in the past 6 months, according to NBC San Diego. Geologists have been brought in. But even after digging up the ground for clues, they haven’t been able to solve the mystery.

Administrators don’t want to take any chances with student safety. But there are just a few weeks left before the start of the new year.

What on earth is going on?

We learned the following about sinkholes from National Geographic:

Sinkholes are cavities in the ground that form when water erodes an underlying rock layer.

Two types of sinkholes exist. One forms when the roof of a cave collapses and exposes the underground cavern. The second type forms when water dissolves the rock underneath soil and creates an underground chasm. Without rock to support it, the soil layer collapses and creates a hole on the surface.

Sinkholes have both natural and human causes. Land made of a soft underground rock layer, such as rock salt around the Dead Sea or limestone in Mexico’s Yucatan Peninsula, are often riddled with sinkholes, since the rock layer is easily dissolved.

Manmade sinkholes are created when city development compromises the structural integrity of underlying rock. Roads, buildings, and other types of construction may cause water to collect in certain areas and wash away the supporting rock layer (especially at low sea levels and after a heavy rainfall).