1857 Fort Tejon earthquake
E831842
The 1857 Fort Tejon earthquake was a massive magnitude ~7.9 rupture along California’s San Andreas Fault that produced some of the largest known ground displacements in U.S. history.
All labels observed (3)
| Label | Occurrences |
|---|---|
| 1857 California earthquake | 1 |
| 1857 Fort Tejon earthquake canonical | 1 |
| Great Fort Tejon earthquake | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T9970847 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: 1857 Fort Tejon earthquake Context triple: [Pacific–North American plate boundary system, notableEarthquake, 1857 Fort Tejon earthquake]
-
A.
1968 Borrego Mountain earthquake
The 1968 Borrego Mountain earthquake was a powerful magnitude 6.5–6.8 temblor in Southern California that caused significant surface rupture and damage, and became an important case study in modern seismology and fault mechanics.
-
B.
1868 Hayward earthquake
The 1868 Hayward earthquake was a powerful and destructive seismic event that struck the San Francisco Bay Area in California, causing extensive damage and loss of life and serving as a key historical benchmark for seismic risk on the Hayward Fault.
-
C.
1983 Coalinga earthquake
The 1983 Coalinga earthquake was a powerful magnitude 6.5 seismic event in central California that caused significant damage to the town of Coalinga and surrounding areas.
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D.
Loma Prieta
Loma Prieta is a prominent peak in California’s Santa Cruz Mountains, best known for lending its name to the devastating 1989 Loma Prieta earthquake.
-
E.
1989 Loma Prieta earthquake
The 1989 Loma Prieta earthquake was a powerful magnitude 6.9 quake in Northern California that caused widespread damage in the San Francisco Bay Area, including freeway collapses and the disruption of the World Series.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: 1857 Fort Tejon earthquake Target entity description: The 1857 Fort Tejon earthquake was a massive magnitude ~7.9 rupture along California’s San Andreas Fault that produced some of the largest known ground displacements in U.S. history.
-
A.
1968 Borrego Mountain earthquake
The 1968 Borrego Mountain earthquake was a powerful magnitude 6.5–6.8 temblor in Southern California that caused significant surface rupture and damage, and became an important case study in modern seismology and fault mechanics.
-
B.
1868 Hayward earthquake
The 1868 Hayward earthquake was a powerful and destructive seismic event that struck the San Francisco Bay Area in California, causing extensive damage and loss of life and serving as a key historical benchmark for seismic risk on the Hayward Fault.
-
C.
1983 Coalinga earthquake
The 1983 Coalinga earthquake was a powerful magnitude 6.5 seismic event in central California that caused significant damage to the town of Coalinga and surrounding areas.
-
D.
Loma Prieta
Loma Prieta is a prominent peak in California’s Santa Cruz Mountains, best known for lending its name to the devastating 1989 Loma Prieta earthquake.
-
E.
1989 Loma Prieta earthquake
The 1989 Loma Prieta earthquake was a powerful magnitude 6.9 quake in Northern California that caused widespread damage in the San Francisco Bay Area, including freeway collapses and the disruption of the World Series.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
earthquake
ⓘ
historical event ⓘ megathrust earthquake ⓘ |
| alsoKnownAs |
1857 California earthquake
ⓘ
linked to:
1857 Fort Tejon earthquake
Great Fort Tejon earthquake ⓘ
linked to:
1857 Fort Tejon earthquake
|
| casualties | at least 2 deaths ⓘ |
| category |
1857 natural disasters in the United States
ⓘ
Earthquakes in California ⓘ San Andreas Fault ⓘ |
| caused |
damage at Fort Tejon
ⓘ
ground fissures ⓘ landslides ⓘ liquefaction in some areas ⓘ surface rupture along San Andreas Fault ⓘ |
| country |
United States
ⓘ
linked to:
United States of America
|
| epicenterNear | Fort Tejon ⓘ |
| fault | San Andreas Fault ⓘ |
| followedBy | 1906 San Francisco earthquake ⓘ |
| intensityScale | Modified Mercalli intensity scale ⓘ |
| isOneOf |
largest historical earthquakes in the contiguous United States
ⓘ
largest known earthquakes on the San Andreas Fault ⓘ |
| locatedIn |
California
ⓘ
linked to:
California, United States
|
| magnitude | 7.9 ⓘ |
| magnitudeType | moment magnitude scale ⓘ |
| maximumIntensity | IX ⓘ |
| maximumSurfaceDisplacement |
about 30 feet
ⓘ
about 9 meters ⓘ |
| notableFor |
long surface rupture length
ⓘ
very large ground displacement ⓘ |
| occurredOn | 1857-01-09 ⓘ |
| partOf | seismic history of California ⓘ |
| plateBoundary | transform plate boundary ⓘ |
| precededBy | 1852 San Andreas Fault earthquake ⓘ |
| recordedBy | historical accounts ⓘ |
| regionAffected |
Central California
ⓘ
Kern County ⓘ Los Angeles region ⓘ
linked to:
Greater Los Angeles Area
San Joaquin Valley ⓘ Santa Barbara County ⓘ Southern California ⓘ |
| ruptureLength |
about 220 miles
ⓘ
about 350 kilometers ⓘ |
| slipType | right-lateral strike-slip ⓘ |
| studiedBy | United States Geological Survey ⓘ |
| tectonicSetting | boundary between Pacific Plate and North American Plate ⓘ |
| time | about 08:20 local time ⓘ |
| tsunami | no significant tsunami reported ⓘ |
| usedFor | estimating San Andreas Fault recurrence intervals ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: 1857 Fort Tejon earthquake Description of subject: The 1857 Fort Tejon earthquake was a massive magnitude ~7.9 rupture along California’s San Andreas Fault that produced some of the largest known ground displacements in U.S. history.
Referenced by (3)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: 1857 Fort Tejon earthquake
linked to: 1857 Fort Tejon earthquake