{
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 "constitutionVersion": "1.0.0",
 "createdAt": "2026-08-12T00:00:00Z",
 "description": "Append-only Evidence Passport records. Old revisions are immutable; corrections create a new revision and preserve the previous permalink.",
 "entity": {
  "type": "project",
  "id": "la-shakealert-app",
  "title": "ShakeAlertLA — the City's Earthquake Warning App",
  "canonicalUrl": "https://1001smartcities.org/projects/la-shakealert-app/"
 },
 "currentRevisionId": "2026-08-20-source-dates",
 "revisions": [
  {
   "id": "2026-08-20-source-dates",
   "createdAt": "2026-08-20T00:00:00Z",
   "effectiveAt": "2026-07-26",
   "changeType": "baseline",
   "summary": "Created the first structured Evidence Passport with 1 claim and 10 source dossiers.",
   "preparedBy": {
    "type": "automation",
    "label": "AI-assisted evidence preparation",
    "humanApproved": false
   },
   "review": {
    "status": "unreviewed",
    "by": null,
    "date": null,
    "note": "Awaiting operator and domain-expert review; publication of this revision implies neither."
   },
   "changes": [
    {
     "operation": "add",
     "path": "/evidencePassport",
     "summary": "Added claim-level evidence mapping and source dossiers."
    },
    {
     "operation": "add",
     "path": "/revisionHistory",
     "summary": "Established a permanent, hash-addressed baseline revision."
    }
   ],
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    "projectFingerprint": "sha256:5cbfcacee3965299e2863fbf1e94d146d7fd9c9352304600c33af65cbee8f145",
    "assurance": {
     "status": "unreviewed",
     "scope": "evidence-passport-revision",
     "statement": "AI-assisted structural preparation. This revision has not been reviewed by a human or subject-matter expert.",
     "machineChecks": [
      "schema",
      "publication-diff-contract",
      "material-project-fingerprint",
      "claim-text-drift",
      "source-reference-resolution",
      "complete-source-dossier",
      "snapshot-hash"
     ]
    },
    "projectState": {
     "status": "completed",
     "outcome": "scaled-back",
     "evidenceGrade": "peer-reviewed",
     "timeline": {
      "started": 2018,
      "ended": 2020
     }
    },
    "governance": {
     "operator": "City of Los Angeles (Information Technology Agency and Emergency Management Department); alerts from the USGS ShakeAlert system",
     "actorTypes": [
      "city-government",
      "national-government"
     ],
     "fundingModel": "mixed",
     "fundingDescription": "City of Los Angeles contract, with the Annenberg Foundation and the Mayor's Fund for Los Angeles as named partners",
     "cost": "≈$300k app contract (AT&T and the GRYD Foundation)",
     "ownership": null,
     "decisionRights": null,
     "exitConditions": null
    },
    "claims": [
     {
      "id": "clm-c7485f5c2f00dfe4",
      "field": "impact",
      "text": "A peer-reviewed USGS-authored analysis found the predicted shaking fell below the app's MMI 4.0 threshold, and that for the M7.1 an alert was warranted but ShakeAlert underestimated the magnitude by 0.8 units",
      "statementKind": "quantitative",
      "textMode": "verbatim-from-project-record",
      "mappingStatus": "mapped",
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      ],
      "supportNote": "The analysis covers the July 2019 Ridgecrest sequence, during which the app sent no public alert to Los Angeles County.",
      "caveat": null,
      "interpretation": {
       "added": false,
       "interpolation": false,
       "note": "The passport copies the published claim and its recorded source mapping without adding a conclusion."
      }
     }
    ],
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     {
      "id": "src-2b2b98cfafb5bf16",
      "title": "City of Los Angeles Information Technology Agency (authority)",
      "url": "https://ita.lacity.gov/news/city-los-angeles-releases-shakealertla-earthquake-early-warning-app",
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      "role": "background",
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      "temporal": {
       "publishedAt": "2019-01-18",
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       "recordLastVerifiedAt": "2026-07-26",
       "dossierCreatedAt": "2026-08-20",
       "retrievedAt": null,
       "status": "publication-and-record-dates-recorded"
      },
      "locator": {
       "type": "descriptive-source-note",
       "value": "The city's own account of the release, built on the USGS ShakeAlert system, and of the later lowering of the warning threshold from magnitude 5.0 to 4.5. Dates the release to 1 January 2019; the app reached the stores on 31 December 2018.",
       "exact": false
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      "title": "Cal OES / Mayor Garcetti — retirement announcement (23 Dec 2020)",
      "url": "https://www.news.caloes.ca.gov/mayor-garcetti-calls-on-angelenos-to-download-myshake",
      "publisher": {
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      "language": "und",
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      "temporal": {
       "publishedAt": "2020-12-23",
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       "type": "descriptive-source-note",
       "value": "Source of the 31 December 2020 retirement date, the self-reported 920,000 downloads and 100,000 alerts issued, the AT&T / Annenberg Foundation / Mayor's Fund partnership, and the statement that the statewide system pairs MyShake with Wireless Emergency Alerts.",
       "exact": false
      },
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     {
      "id": "src-39fe7124655ca2a0",
      "title": "Chung et al., Bulletin of the Seismological Society of America (2020) — peer-reviewed",
      "url": "https://www.usgs.gov/publications/shakealert-earthquake-early-warning-system-performance-during-2019-ridgecrest",
      "publisher": {
       "name": null,
       "domain": "usgs.gov",
       "classification": "not-classified"
      },
      "sourceType": "web-page",
      "language": "und",
      "role": "claim-evidence",
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      "locator": {
       "type": "descriptive-source-note",
       "value": "BSSA 110(4):1904-1923, doi 10.1785/0120200032. Carries both load-bearing findings: no public alert was sent because predicted shaking was below the app's MMI 4.0 threshold, and for the M7.1 an alert was warranted but the point-source and finite-fault algorithms underestimated the magnitude by 0.8 units. Also confirms the app was the only publicly available alerting method at the time. Publisher pages block automated fetching (403); text verified via indexed abstract.",
       "exact": false
      },
      "preservation": {
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     {
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      "title": "GovTech — ShakeAlertLA adjusts alert thresholds after users complain",
      "url": "https://www.govtech.com/dc/articles/shakealertla-adjusts-alerft-thresholds-after-users-complain.html",
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      "locator": {
       "type": "descriptive-source-note",
       "value": "Launch threshold of magnitude 5.0 plus MMI IV, and the city's own rationale for setting it high: officials feared people would become apathetic and stop responding if it was set too low. Reports the MMI threshold as unchanged, which is why no revised intensity value is claimed here.",
       "exact": false
      },
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      "id": "src-29a299841e84f202",
      "title": "NBC Los Angeles — threshold lowered (14 Aug 2019)",
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       "publishedAt": "2019-08-14",
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       "type": "descriptive-source-note",
       "value": "Dates the change to Wednesday 14 August 2019 and attributes it jointly to Mayor Garcetti and the USGS: magnitude 5.0 down to 4.5.",
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      "title": "CBS Los Angeles — city council approves the app contract (19 Jun 2018)",
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       "value": "The $300,000 contract with AT&T and the GRYD Foundation for design, creation and deployment of the app.",
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      },
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     },
     {
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      "title": "CBS Los Angeles — 'We hear you' (4 Jul 2019)",
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       "publishedAt": "2019-07-04",
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      },
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       "type": "descriptive-source-note",
       "value": "The city's same-day response to the Ridgecrest non-alert, promising to lower the threshold.",
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      },
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     },
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      "title": "Nextgov — L.A.'s public earthquake-warning app is the first in the U.S. (Jan 2019)",
      "url": "https://www.nextgov.com/emerging-tech/2019/01/ls-public-earthquake-warning-app-first-us/154001/",
      "publisher": {
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      },
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       "publishedAt": "2019-01-08",
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       "retrievedAt": null,
       "status": "publication-and-record-dates-recorded"
      },
      "locator": {
       "type": "descriptive-source-note",
       "value": "Independent support for the first-in-the-nation claim and for the partner list; also records that dozens of early users reported the iPhone app crashing at launch.",
       "exact": false
      },
      "preservation": {
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      }
     },
     {
      "id": "src-1606abec73a62cec",
      "title": "LAist — the city points everyone to the statewide app (Dec 2020)",
      "url": "https://laist.com/news/shakealertla-end-city-warning-statewide-shakealert",
      "publisher": {
       "name": null,
       "domain": "laist.com",
       "classification": "not-classified"
      },
      "sourceType": "web-page",
      "language": "und",
      "role": "background",
      "claimRefs": [],
      "temporal": {
       "publishedAt": "2020-12-23",
       "updatedAt": null,
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       "recordLastVerifiedAt": "2026-07-26",
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       "retrievedAt": null,
       "status": "publication-and-record-dates-recorded"
      },
      "locator": {
       "type": "descriptive-source-note",
       "value": "Garcetti's stated reason, that ShakeAlertLA was a bridge to the statewide system, and confirmation that MyShake is operated by UC Berkeley.",
       "exact": false
      },
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       "contentHash": null,
       "status": "not-captured"
      }
     },
     {
      "id": "src-81e2b66e5de16c32",
      "title": "Temblor — earthquake early warning now and beyond",
      "url": "https://temblor.net/earthquake-insights/earthquake-early-warning-google-myshake-shakealert-update-14780/",
      "publisher": {
       "name": null,
       "domain": "temblor.net",
       "classification": "not-classified"
      },
      "sourceType": "web-page",
      "language": "und",
      "role": "background",
      "claimRefs": [],
      "temporal": {
       "publishedAt": "2022-12-20",
       "updatedAt": null,
       "sourceCheckedAt": null,
       "recordLastVerifiedAt": "2026-07-26",
       "dossierCreatedAt": "2026-08-20",
       "retrievedAt": null,
       "status": "publication-and-record-dates-recorded"
      },
      "locator": {
       "type": "descriptive-source-note",
       "value": "The only quantified Los Angeles performance figures found, and they belong to the successor app: at the M4.5 El Monte quake of 19 September 2020, MyShake sent 20,169 alerts, reached 80% of phones 3.5 seconds after receiving the ShakeAlert signal, and about half of alerted users were notified before the S-wave arrived. Also identifies WEA as FEMA's channel.",
       "exact": false
      },
      "preservation": {
       "archiveUrl": null,
       "archivedAt": null,
       "contentHash": null,
       "status": "not-captured"
      }
     }
    ],
    "coverage": {
     "claimsTotal": 1,
     "claimsMapped": 1,
     "sourcesTotal": 10,
     "sourcesUsedByClaims": 1,
     "sourcesWithPublicationDate": 10,
     "sourcesWithArchive": 1,
     "sourcesWithExactLocator": 0,
     "sourcesWithContentHash": 0
    },
    "limits": [
     "Publisher names and source languages have not yet been classified; domains are recorded without guessing.",
     "Existing source notes are descriptive locators, not page- or paragraph-exact citations.",
     "A missing archive, publication date or content hash is shown as null rather than inferred.",
     "The project-level evidence grade ranks the strongest source in the entry; it is not a truth score for every claim."
    ]
   }
  }
 ]
}