1999 Hector Mine earthquake
E1008730
The 1999 Hector Mine earthquake was a powerful magnitude 7.1 strike-slip earthquake in the Mojave Desert of Southern California that caused widespread ground rupture and was one of the largest earthquakes in the region in the late 20th century.
All labels observed (1)
| Label | Occurrences |
|---|---|
| 1999 Hector Mine earthquake canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T12854239 — 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: 1999 Hector Mine earthquake Context triple: [Eastern California Shear Zone, notableEarthquake, 1999 Hector Mine earthquake]
-
A.
1992 Landers earthquake
The 1992 Landers earthquake was a powerful magnitude 7.3 strike-slip earthquake in Southern California that ruptured multiple faults, caused widespread damage, and significantly advanced understanding of complex fault systems.
-
B.
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.
-
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.
1857 Fort Tejon earthquake
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.
-
E.
1994 Northridge earthquake
The 1994 Northridge earthquake was a powerful and destructive magnitude 6.7 earthquake that struck the Los Angeles area of Southern California on January 17, 1994, causing widespread damage and loss of life.
- 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: 1999 Hector Mine earthquake Target entity description: The 1999 Hector Mine earthquake was a powerful magnitude 7.1 strike-slip earthquake in the Mojave Desert of Southern California that caused widespread ground rupture and was one of the largest earthquakes in the region in the late 20th century.
-
A.
1992 Landers earthquake
The 1992 Landers earthquake was a powerful magnitude 7.3 strike-slip earthquake in Southern California that ruptured multiple faults, caused widespread damage, and significantly advanced understanding of complex fault systems.
-
B.
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.
-
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.
1857 Fort Tejon earthquake
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.
-
E.
1994 Northridge earthquake
The 1994 Northridge earthquake was a powerful and destructive magnitude 6.7 earthquake that struck the Los Angeles area of Southern California on January 17, 1994, causing widespread damage and loss of life.
- F. None of above. chosen
Statements (47)
| Predicate | Object |
|---|---|
| instanceOf |
earthquake
ⓘ
strike-slip earthquake ⓘ |
| aftershocks | thousands of aftershocks over subsequent months ⓘ |
| casualties | no direct fatalities ⓘ |
| category |
1999 earthquakes
ⓘ
1999 natural disasters in the United States ⓘ Earthquakes in California ⓘ |
| caused | offset of roads and railroad tracks ⓘ |
| country |
United States of America
ⓘ
surface form:
United States
|
| damage |
damage to roads and rail lines
ⓘ
ground cracking and liquefaction in some areas ⓘ light to moderate structural damage ⓘ |
| date |
1999-10-16
ⓘ
October 16, 1999 ⓘ |
| depth | about 20 km ⓘ |
| distanceFrom |
about 44 km north of Joshua Tree, California
ⓘ
about 47 km east of Barstow, California ⓘ |
| epicenterNear |
Hector Mine
NERFINISHED
ⓘ
Twentynine Palms, California NERFINISHED ⓘ |
| faultType | strike-slip ⓘ |
| injuries | minor injuries ⓘ |
| localTime | 02:46:44 PDT ⓘ |
| locatedIn |
California, United States
ⓘ
surface form:
California
Mojave Desert ⓘ San Bernardino County ⓘ
surface form:
San Bernardino County, California
Southern California ⓘ |
| maximumMercalliIntensity | VII (Very strong) ⓘ |
| maximumSurfaceDisplacement | about 5.5 m ⓘ |
| momentMagnitude | 7.1 ⓘ |
| notableFor |
extensive surface fault rupture in a sparsely populated area
ⓘ
one of the largest late 20th-century earthquakes in Southern California ⓘ |
| observedWith | strong-motion seismographs across Southern California ⓘ |
| occurredInTectonicSetting | transform plate boundary between Pacific Plate and North American Plate ⓘ |
| partOf | seismicity of the Eastern California Shear Zone ⓘ |
| precededBy | 1992 Landers earthquake NERFINISHED ⓘ |
| recordedBy | United States Geological Survey NERFINISHED ⓘ |
| region | Eastern California Shear Zone NERFINISHED ⓘ |
| rupturedFault |
Bullion fault
NERFINISHED
ⓘ
Hector Mine fault zone NERFINISHED ⓘ Lavic Lake fault NERFINISHED ⓘ |
| scientificSignificance |
important for studies of triggered seismicity and fault interaction
ⓘ
used to study dynamic triggering of distant earthquakes ⓘ |
| seismicMoment | on the order of 10^19 N·m ⓘ |
| surfaceRuptureLength | about 40 km ⓘ |
| time | 09:46:44 UTC ⓘ |
| triggeredBy | 1992 Landers earthquake (static stress changes) ⓘ |
| USGSEventId | ci14383980 ⓘ |
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: 1999 Hector Mine earthquake Description of subject: The 1999 Hector Mine earthquake was a powerful magnitude 7.1 strike-slip earthquake in the Mojave Desert of Southern California that caused widespread ground rupture and was one of the largest earthquakes in the region in the late 20th century.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.