Of late, there has been a flurry of articles about the caves located in the cliffs on the west side of More Mesa. These stories have been precipitated by a recent and unfortunate incident of a young man being severely injured by a falling rock in one of these caves. While we cannot offer solutions to prevent this from ever occurring again, we can offer some fact-based scientific information about why it is extremely dangerous and unwise to traverse down to the beach or visit, and especially linger, in any of these caves.
Geology Facts: The cliffs of More Mesa are distinctly different on the east and west sides. The east side cliffs consist of Monterey Shale, a clay formation that is 6-18 million years old. This section of the cliff erodes slowly and its 100 foot drop to the beach below is along a sloping grade.
However, the west side of the cliff face is of the Santa Barbara Formation, a younger sedimentary formation of marine sand that is only 700,000 years old. (The big blobby tar seeps oozing onto the More Mesa beach are from the Santa Barbara formation.)
This younger material erodes very quickly. Indeed, sea cliff retreat in the Santa Barbara Formation has been demonstrated to be about 10 inches a year, the highest rate observed along this portion of the South Coast. What this all means is that the western cliff is steep, unstable and unpredictable. Further …
• The western cliff should never be used to access the beach
• Visitors to More Mesa beach should never use areas close to the western cliffs
• The caves should never be occupied.
One further cautionary note … when it starts raining again, do not use the trail closest to the cliff face after a rain. It may disappear as you are admiring the view. Please be careful!