Earthquakes, induced seismicity and Oklahoma foundations

What changed, and what the science says

The USGS says "recent increases in earthquake occurrence rates in Oklahoma have been linked to the injection of large volumes of saltwater, a byproduct of oil and gas extraction".

Rates across the central and eastern United States rose sharply from around 2009 and peaked in 2015. They have since declined substantially, though they remain above the long-run historical baseline. The Oklahoma Geological Survey maintains the state earthquake catalog and monitors seismicity (Oklahoma Geological Survey).

Two honest caveats. A declining rate is not a zero rate, and "my house has cracks and Oklahoma has earthquakes" is not causation. Most Oklahoma foundation movement is still a clay and moisture story. Seismicity is a real additional factor here, not a replacement explanation.

What earthquake damage tends to look like

• Sudden onset. Damage that appeared over a day, not over a season, and that residents can date to a felt event.
• Damage clustered in brittle elements, masonry chimneys, brick veneer, plaster and unreinforced masonry, rather than the gradual signature of settlement.
• No accompanying moisture story. No leak, no drainage change, no drought cycle to explain it.
• Neighbors reporting the same thing in the same week, which is a strong signal and worth asking about.
• Pre-existing weakness made worse. Shaking often finds the crack that clay movement started, which is why documentation before and after matters.

Document it the day it happens

1. Photograph everything with dates, wide shots and close-ups with a scale, inside and out, before anything is cleaned or patched.
2. Write down the event, the date and time you felt it and what you observed, while it is fresh.
3. Do not repair before it is inspected, because patched evidence is weak evidence.
4. Get an independent engineer to assess causation, not the repair contractor. Causation is the contested question in any claim, so the opinion should come from someone with no stake in the repair.
5. Notify your insurer promptly and ask specifically which cover applies, before you agree any work.

Insurance is the part that catches people out

Standard homeowners policies in the United States typically exclude earth movement, which usually covers both earthquake and ordinary settling. Earthquake cover is normally a separate endorsement or policy with its own deductible. That deductible is often a percentage of the dwelling limit rather than a flat dollar amount.

So a household can have earthquake cover and still find the deductible exceeds a modest claim. We are not naming a figure because policy wordings genuinely differ. Read your declarations page and endorsements, and ask your agent these three questions in writing.

Do I have earthquake cover at all?

It is generally an add-on, not a default. Absence is common and is not a mistake by your agent unless you asked for it.

What is my earthquake deductible, in dollars?

Percentage deductibles are normal here. Ask for the actual dollar figure against your current dwelling limit, not the percentage.

Is settling or earth movement excluded elsewhere in my policy?

Ordinary settlement is typically excluded whether or not you carry earthquake cover, which is precisely why establishing the cause matters so much.

If a contractor tells you it was the earthquake

Ask how they know, and ask it politely but specifically. Causation is an engineering opinion, and it is one with financial consequences for the person offering it. If you intend to make a claim, the assessment should come from an independent licensed professional engineer whose fee does not depend on the answer.