US Quakes — credits and licenses
==================================

Every map layer and every earthquake in this app is public-domain data, credited below with what
this app changed. The history of earthquakes was downloaded from the USGS event service for four map
boxes and packed to 2026-01-01; the live file (data/snapshot.json) is refreshed from the USGS feed
and carries its own list of sources and times. Nothing here is fetched at runtime: the app has no
network.

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ANSS COMPREHENSIVE EARTHQUAKE CATALOG (COMCAT), AND ITS GEOJSON SUMMARY FEEDS

    Owner: U.S. Geological Survey, Earthquake Hazards Program (with the ANSS regional networks)
    Source: FDSN event web service https://earthquake.usgs.gov/fdsnws/event/1/query, API version
            2.7.0, CSV, 120 closed windows (398 018 rows of every event type, 72 219 141 B), each
            pinned by sha256 in scripts/us_quakes/catalog-windows.json
    URL: https://earthquake.usgs.gov/fdsnws/event/1
    License: Public domain (US Government work, 17 U.S.C. §105); USGS asks for credit
             "USGS-authored or produced data and information are considered to be in the U.S. Public
             Domain." "Most U.S. Geological Survey (USGS) information resides in the Public Domain
             and may be used without restriction. When using information from USGS information
             products, publications, or websites, we ask that proper credit be given." (usgs.gov,
             Copyrights and Credits; Acknowledging or Crediting USGS)
    Retrieved: 2026-09-30
    Adaptations: earthquakes only (the catalog's type "earthquake"): every one before 1900 and
                 magnitude 2.5 and up from 1900 to 2026-01-01, in four map boxes, de-duplicated by
                 id
                 rounded: time to the minute (truncated), longitude to 0.002°, latitude to 0.001°,
                 depth to 10 m (10.00 km kept for the catalog's exact 10; a depth that only rounds
                 to it is written 9.99 or 10.01 km), magnitude to a tenth (half up); ids and place
                 names kept for magnitude 4.5 and up
                 repacked as little-endian binary columns (assets/history.bin, described by
                 history.json)
    Cite: U.S. Geological Survey, 2017, Advanced National Seismic System (ANSS) Comprehensive
          Catalog, doi:10.5066/F7MS3QZH.
    Attribution: Earthquakes: U.S. Geological Survey, ANSS Comprehensive Earthquake Catalog
                 (ComCat), doi:10.5066/F7MS3QZH; rounded and repacked.

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3D ELEVATION PROGRAM (3DEP) BARE EARTH DEM, MULTIDIRECTIONAL HILLSHADE

    Owner: U.S. Geological Survey, National Geospatial Program (The National Map)
    Source: exportImage from the 3DEPElevation ImageServer, rendering rule "Hillshade
            Multidirectional", PNG, Web Mercator; five exports (conus, ak-west, ak-east, hi, pr)
            pinned by sha256 in scripts/us_quakes/sources.py (RELIEF_PINS)
            the same boxes as Int16 elevation for the land mask (RELIEF_DEM_PINS); the extents the
            server reported, in scripts/us_quakes/relief-extents.json
    URL: https://elevation.nationalmap.gov/arcgis/rest/services/3DEPElevation/ImageServer
    License: Public domain (US Government work); The National Map asks for an acknowledgment
             "Map services and data downloaded from The National Map are free and in the public
             domain. There are no restrictions; however, we request that the following
             acknowledgment statement of the originating agency be included in products and data
             derived from our map services when citing, copying, or reprinting: "Map services and
             data available from U.S. Geological Survey, National Geospatial Program."" (usgs.gov
             FAQ, terms of use for The National Map)
    Retrieved: 2026-09-30
    Adaptations: masked to land by the 3DEP elevation of the same box (sea and NoData left unshaded)
                 and by Natural Earth 1:50m lakes
                 hillshade levels stretched from the 0.5th percentile of land pixels; Alaska's two
                 exports joined on one grid and scaled to 0.75
                 re-encoded as gray JPEG, quality 75 (assets/relief-*.jpg)
    Cite: U.S. Geological Survey, USGS 3D Elevation Program Digital Elevation Model, accessed
          September 30, 2026, at
          https://elevation.nationalmap.gov/arcgis/rest/services/3DEPElevation/ImageServer.
    Attribution: Relief: USGS 3D Elevation Program. Map services and data available from U.S.
                 Geological Survey, National Geospatial Program.

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QUATERNARY FAULT AND FOLD DATABASE OF THE UNITED STATES

    Owner: U.S. Geological Survey, with state geological surveys
    Source: Qfaults_GIS.zip (32 371 696 B, sha256
            447eadc5926256710d988c30e5996ba540604caa0154f9746c48bad637926893), from
            https://earthquake.usgs.gov/static/lfs/nshm/qfaults/Qfaults_GIS.zip; read:
            GDB/Qfaults_2020_WGS84.gdb layer Qfaults_2020 (112 944 lines, 2025 edits) with pyogrio;
            the SHP/ copy (112 809) predates those edits (RESEARCH.md §2.4)
    URL: https://earthquake.usgs.gov/static/lfs/nshm/qfaults/Qfaults_GIS.zip
    License: Public domain; the metadata sets no use or access constraint
             FGDC metadata in the ZIP: <useconst>none</useconst>, <accconst>none</accconst>. USGS
             faults page: "Sources/Usage: Public Domain." and "When you use this data, please
             provide proper acknowledgment."
    Retrieved: 2026-09-30
    Adaptations: 112 944 fault traces grouped into 5 815 records by fault, section and their age,
                 slip-rate, slip-sense, line-type, class and review-year labels (as the database
                 spells them; "Late Quaternary" joined to "late Quaternary")
                 lines simplified at 50 000 m² and rounded to 0.001°; the fault_url links are not
                 shipped (the search they point at was retired on February 26, 2026)
    Cite: U.S. Geological Survey, 2020, Quaternary Fault and Fold Database for the Nation, accessed
          September 30, 2026, at https://doi.org/10.5066/P9BCVRCK.
    Attribution: Faults: USGS and state geological surveys, Quaternary Fault and Fold Database of
                 the United States (U.S. Geological Survey, 2020, doi:10.5066/P9BCVRCK).

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USGS VOLCANO HAZARDS PROGRAM, HANS PUBLIC API (US VOLCANO LIST AND MONITORED STATUS)

    Owner: U.S. Geological Survey, Volcano Hazards Program
    Source: getUSVolcanoes (https://volcanoes.usgs.gov/hans-public/api/volcano/getUSVolcanoes),
            saved as scripts/us_quakes/samples/volcano-getUSVolcanoes.json (170 146 B, sha256
            a5bd45dd128b273dd554cac7ec5c7fc26c070e8df2d683a75084333ba9b92c4f)
    URL: https://volcanoes.usgs.gov/hans-public/api/volcano/
    License: Public domain (US Government work); the API carries no guarantee of support
             "USGS-authored or produced data and information are considered to be in the U.S. Public
             Domain." "Most U.S. Geological Survey (USGS) information resides in the Public Domain
             and may be used without restriction. When using information from USGS information
             products, publications, or websites, we ask that proper credit be given." (usgs.gov,
             Copyrights and Credits; Acknowledging or Crediting USGS) The API: "These items are
             freely available but are designed to support USGS applications. No guarantee of
             continuing support should be assumed."
    Retrieved: 2026-09-30
    Adaptations: the 148 of 170 US volcanoes inside the four map boxes; name, position, elevation,
                 threat class and observatory kept; web links not shipped
    Cite: U.S. Geological Survey, Volcano Hazards Program, HANS public API, getUSVolcanoes, accessed
          September 30, 2026.
    Attribution: Volcano status: USGS Volcano Hazards Program.

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NATURAL EARTH V5.1.2 (1:10M COASTLINE, LAND, LAKES, BOUNDARIES AND BATHYMETRY; 1:50M POPULATED PLACES)

    Owner: Natural Earth (naturalearthdata.com), free vector and raster map data
    Source: ne_10m_coastline.geojson (10 110 735 B, sha256
            6f75ae0e0de157b14946e2255eb1f5486d9a13819032e26d4610852d296788f6)
            ne_10m_land.geojson (10 157 965 B, sha256
            1ac90796408bc6ad6911d69448485d3c4dbf2190370080368a09976e1c9f7416)
            ne_10m_lakes.geojson (5 043 554 B, sha256
            2d036f53dedec578001c5c30c2959ee7d4eebc1306900fa4367c49929ec8f2d9)
            ne_10m_admin_0_boundary_lines_land.geojson (2 284 669 B, sha256
            74d9c16229c095fde65943a9919e337682f044bcebccb120764f38edf3b70f4a)
            ne_10m_admin_1_states_provinces_lines.geojson (21 092 537 B, sha256
            1a1f30ccaaf4cc9c4bde34266f0b8cbb955d3a4cf254b756912255f2ec7c75b6)
            ne_50m_lakes.geojson (876 018 B, sha256
            d350b75978b26fe839b797c2c529b2fb8f47fb3983c03f4964e36d5df9378a52), used only for the
            relief's lake mask and to choose the 1:10m lakes drawn, not shipped
            ne_50m_admin_1_states_provinces_lines.geojson (882 513 B, sha256
            72cca93c850d412628a5da4bc5ebfe21ba4d376eb34611bde6b623ee73f0fdcf), used only to choose
            the countries whose state lines are drawn, not shipped
            ne_50m_populated_places_simple.geojson (850 767 B, sha256
            8e70756b39fae9bcdc1e332bfc510c024c5edd3a13203ffd20092ee37b61d978)
            ne_10m_bathymetry_K_200.geojson (4 229 885 B, sha256
            5c6c182da8608153ea2dce22dfb32c987e5390e0bd4a122266143ba181a7b636)
            ne_10m_bathymetry_J_1000.geojson (2 509 878 B, sha256
            fa30219901dd4de34b9f5b20f41bc7c055f9fc9d58cf157ad2679c95239cd366)
            ne_10m_bathymetry_I_2000.geojson (4 280 462 B, sha256
            cdedc746ce06e1a051cb8905e8f07855225ccbd3560ce3a66607651fc6953ce2)
            ne_10m_bathymetry_H_3000.geojson (8 479 402 B, sha256
            28fda8b34dfb8615f9644bff3e56c184501e21dccb807d428432e56d8dac0cf5)
            ne_10m_bathymetry_G_4000.geojson (12 182 812 B, sha256
            ad876e6b6b686494a0e89f0096880a6755aee77af3d738794bbbc92216afcf3d)
            ne_10m_bathymetry_F_5000.geojson (9 759 029 B, sha256
            e7b663f3f6144c1d23b8205618fd1eeb5256c4b03785a8ed009178209d68ba72)
            ne_10m_bathymetry_E_6000.geojson (1 006 550 B, sha256
            75fc34afdd5bc54a3ebe093fc0a680af70cf255f1b3e7e80ad75e795f5cc4c8d)
            ne_10m_bathymetry_D_7000.geojson (100 076 B, sha256
            19eb5dd59d37d6c6da9b0d04252769c62708aad6a1578f16d6a7b8b30fd05c56)
            from the natural-earth-vector repository at commit
            f1890d9f152c896d250a77557a5751a93d494776 (tag v5.1.2)
    URL: https://github.com/nvkelso/natural-earth-vector/tree/f1890d9f152c896d250a77557a5751a93d494776
    License: Public domain by its authors' dedication
             "All versions of Natural Earth raster + vector map data found on this website are in
             the public domain. You may use the maps in any manner, including modifying the content
             and design, electronic dissemination, and offset printing." "No permission is needed to
             use Natural Earth. Crediting the authors is unnecessary." (LICENSE.md at the pinned
             commit)
    Retrieved: 2026-09-30
    Adaptations: clipped to the map's extent (168°E to 55°W, 25°S to 81°N), cut at 180° and put on
                 one continuous longitude axis
                 land, coast, lakes and boundaries at 1:10m, cut to what 1:50m drew: its lakes (by
                 Natural Earth's ne_id, and the 1:50m water 1:10m files under another id), its nine
                 countries' state lines less the indicators across water, the borders less the
                 Guantánamo lease limit
                 simplified (Visvalingam-Whyatt: 250 000 m² for 1:10m land, coast, lakes and
                 boundaries; 5 km² for the depth bands, whose rings under 50 km² are dropped) from
                 172°E to 64°W and 14° to 75°N, ten times coarser elsewhere north of 5°N and eighty
                 times south of it; coordinates rounded to 0.001°; packed as encoded polylines
                 (assets/geo.json)
                 189 populated places inside the box, with name, rank and region
    Cite: Natural Earth, v5.1.2, commit f1890d9f152c896d250a77557a5751a93d494776.
    Attribution: Basemap: Made with Natural Earth (public domain).

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TEXT QUOTED IN ABOUT AND THE STORIES

    Every explanation of a USGS field and every claim in the stories beyond the catalog's own
    numbers is quoted verbatim from these USGS pages (public domain); the quotes are kept in
    scripts/us_quakes/credits/usgs-statements.txt in the template repository.

    Why are we having so many earthquakes? (FAQ). U.S. Geological Survey.
      https://www.usgs.gov/faqs/why-are-we-having-so-many-or-so-few-earthquakes-has-naturally-occurring-earthquake-activity
      (retrieved 2026-09-30)
    Mining seismicity: goals (USGS/NEIC). U.S. Geological Survey.
      https://earthquake.usgs.gov/data/mineblast/goals.php (retrieved 2026-09-30)
    Why do USGS earthquake magnitudes differ from those published by other agencies? (FAQ). U.S.
      Geological Survey.
      https://www.usgs.gov/faqs/why-do-usgs-earthquake-magnitudes-differ-those-published-other-agencies
      (retrieved 2026-09-30)
    Why do some earthquakes disappear from the map/list? (FAQ). U.S. Geological Survey.
      https://www.usgs.gov/faqs/why-do-some-earthquakes-disappear-maplist (retrieved 2026-09-30)
    Why do so many earthquakes occur at a depth of 10km? (FAQ). U.S. Geological Survey.
      https://www.usgs.gov/faqs/why-do-so-many-earthquakes-occur-a-depth-10km (retrieved 2026-09-30)
    What does it mean that the earthquake occurred at a depth of 0 km? How can an earthquake have a
      negative depth; that would mean it’s in the air. What is the geoid, and what does it have to
      do with earthquake depth? (FAQ). U.S. Geological Survey.
      https://www.usgs.gov/faqs/what-does-it-mean-earthquake-occurred-a-depth-0-km-how-can-earthquake-have-a-negative-depth
      (retrieved 2026-09-30). Two sentences of the answer, in its order; “…” marks the paragraphs
      between them..
    Quaternary Fault and Fold Database of the United States. U.S. Geological Survey.
      https://www.usgs.gov/programs/earthquake-hazards/faults (retrieved 2026-09-30)
    ComCat Event Terms: status. U.S. Geological Survey.
      https://web.archive.org/web/20250104202825/https://earthquake.usgs.gov/data/comcat/index.php
      (retrieved 2026-09-30). USGS ComCat documentation, Event Terms, as archived by the Internet
      Archive on 2025-01-04; the live address https://earthquake.usgs.gov/data/comcat/index.php no
      longer carries the glossary (checked 2026-09-30).
    ComCat Event Terms: felt. U.S. Geological Survey.
      https://web.archive.org/web/20250104202825/https://earthquake.usgs.gov/data/comcat/index.php
      (retrieved 2026-09-30). USGS ComCat documentation, Event Terms, as archived by the Internet
      Archive on 2025-01-04; the live address https://earthquake.usgs.gov/data/comcat/index.php no
      longer carries the glossary (checked 2026-09-30).
    Did You Feel It?. U.S. Geological Survey. https://earthquake.usgs.gov/data/dyfi/ (retrieved
      2026-09-30)
    ComCat Event Terms: tsunami. U.S. Geological Survey.
      https://web.archive.org/web/20250104202825/https://earthquake.usgs.gov/data/comcat/index.php
      (retrieved 2026-09-30). USGS ComCat documentation, Event Terms, as archived by the Internet
      Archive on 2025-01-04; the live address https://earthquake.usgs.gov/data/comcat/index.php no
      longer carries the glossary (checked 2026-09-30).
    ComCat Event Terms: alert. U.S. Geological Survey.
      https://web.archive.org/web/20250104202825/https://earthquake.usgs.gov/data/comcat/index.php
      (retrieved 2026-09-30). USGS ComCat documentation, Event Terms, as archived by the Internet
      Archive on 2025-01-04; the live address https://earthquake.usgs.gov/data/comcat/index.php no
      longer carries the glossary (checked 2026-09-30).
    PAGER. U.S. Geological Survey. https://earthquake.usgs.gov/data/pager/ (retrieved 2026-09-30)
    ComCat Event Terms: sig. U.S. Geological Survey.
      https://web.archive.org/web/20250104202825/https://earthquake.usgs.gov/data/comcat/index.php
      (retrieved 2026-09-30). USGS ComCat documentation, Event Terms, as archived by the Internet
      Archive on 2025-01-04; the live address https://earthquake.usgs.gov/data/comcat/index.php no
      longer carries the glossary (checked 2026-09-30).
    ComCat Event Terms: magType. U.S. Geological Survey.
      https://web.archive.org/web/20250104202825/https://earthquake.usgs.gov/data/comcat/index.php
      (retrieved 2026-09-30). USGS ComCat documentation, Event Terms, as archived by the Internet
      Archive on 2025-01-04; the live address https://earthquake.usgs.gov/data/comcat/index.php no
      longer carries the glossary (checked 2026-09-30).
    ComCat Event Terms: depth. U.S. Geological Survey.
      https://web.archive.org/web/20250104202825/https://earthquake.usgs.gov/data/comcat/index.php
      (retrieved 2026-09-30). USGS ComCat documentation, Event Terms, as archived by the Internet
      Archive on 2025-01-04; the live address https://earthquake.usgs.gov/data/comcat/index.php no
      longer carries the glossary (checked 2026-09-30).
    Magnitude Types. U.S. Geological Survey.
      https://www.usgs.gov/programs/earthquake-hazards/magnitude-types (retrieved 2026-09-30)
    Quaternary Fault and Fold Database: Fault Classes. U.S. Geological Survey.
      https://www.usgs.gov/programs/earthquake-hazards/faults (retrieved 2026-09-30)
    Alert Level System (Volcano Hazards Program). U.S. Geological Survey.
      https://www.usgs.gov/programs/VHP/alert-level-system (retrieved 2026-09-30)
    The orphan tsunami of 1700—Japanese clues to a parent earthquake in North America (Professional
      Paper 1707), abstract. U.S. Geological Survey. https://pubs.usgs.gov/publication/pp1707
      (retrieved 2026-09-30)
    Summary of 1811-1812 New Madrid Earthquakes Sequence. U.S. Geological Survey.
      https://www.usgs.gov/programs/earthquake-hazards/science/summary-1811-1812-new-madrid-earthquakes-sequence
      (retrieved 2026-09-30)
    How long was the 1906 rupture?. U.S. Geological Survey.
      https://earthquake.usgs.gov/earthquakes/events/1906calif/18april/howlong.php (retrieved
      2026-09-30)
    M9.2 Alaska Earthquake and Tsunami of March 27, 1964. U.S. Geological Survey.
      https://earthquake.usgs.gov/earthquakes/events/alaska1964/ (retrieved 2026-09-30)
    Oklahoma has had a surge of earthquakes since 2009. Are they due to fracking? (FAQ). U.S.
      Geological Survey.
      https://www.usgs.gov/faqs/oklahoma-has-had-a-surge-earthquakes-2009-are-they-due-fracking
      (retrieved 2026-09-30)
    The 2018 rift eruption and summit collapse of Kilauea Volcano (publication abstract). U.S.
      Geological Survey.
      https://www.usgs.gov/publications/2018-rift-eruption-and-summit-collapse-kilauea-volcano
      (retrieved 2026-09-30)
    Remembering Ridgecrest. U.S. Geological Survey.
      https://www.usgs.gov/news/featured-story/remembering-ridgecrest (retrieved 2026-09-30)

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FONTS

    Atkinson Hyperlegible: Copyright 2020 Braille Institute of America, Inc.
    Red Hat Mono: Copyright 2024 The Red Hat Project Authors (github.com/RedHatOfficial/RedHatFont)
    Both under the SIL Open Font License 1.1, whose text ships as fonts/OFL.txt. Files:
      atkinson-hyperlegible-latin-400-normal.woff2, atkinson-hyperlegible-latin-700-normal.woff2,
      atkinson-hyperlegible-latin-ext-400-normal.woff2,
      atkinson-hyperlegible-latin-ext-700-normal.woff2, red-hat-mono-latin-500-normal.woff2;
      unchanged from the Fontsource packages @fontsource/atkinson-hyperlegible@5.2.8 and
      @fontsource/red-hat-mono@5.3.0.

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This app is not an earthquake or tsunami warning service.
