{
  "schema_version": 1,
  "description": "Source-linked event catalog for the Sumerian King List paleoclimate alignment explorer. The primary analysis role is restricted to paleoclimate transition events; sea-level pulses, MIS boundaries, and other event classes are sensitivity or exploratory only.",
  "date_convention": "ka BP means thousand years before 1950 CE.",
  "primary_catalog_rule": "analysis_role == primary_paleoclimate and contested == false and 0 <= date_ka_bp <= 260. Primary tier is selected from the explicit analysis_role and contested fields, not inferred from category names.",
  "events": [
    {
      "id": "h1",
      "name": "H1",
      "category": "heinrich",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 16.8,
      "sigma_ka": 0.5,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Hemming 2004",
      "source_url": "https://www.whoi.edu/cms/files/Hemming_2004_282086.pdf",
      "notes": ""
    },
    {
      "id": "h2",
      "name": "H2",
      "category": "heinrich",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 24.0,
      "sigma_ka": 0.5,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Hemming 2004",
      "source_url": "https://www.whoi.edu/cms/files/Hemming_2004_282086.pdf",
      "notes": ""
    },
    {
      "id": "h3",
      "name": "H3",
      "category": "heinrich",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 31.0,
      "sigma_ka": 1.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Hemming 2004",
      "source_url": "https://www.whoi.edu/cms/files/Hemming_2004_282086.pdf",
      "notes": ""
    },
    {
      "id": "h4",
      "name": "H4",
      "category": "heinrich",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 38.0,
      "sigma_ka": 0.5,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Hemming 2004",
      "source_url": "https://www.whoi.edu/cms/files/Hemming_2004_282086.pdf",
      "notes": ""
    },
    {
      "id": "h5",
      "name": "H5",
      "category": "heinrich",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 45.0,
      "sigma_ka": 1.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Hemming 2004",
      "source_url": "https://www.whoi.edu/cms/files/Hemming_2004_282086.pdf",
      "notes": ""
    },
    {
      "id": "h6",
      "name": "H6",
      "category": "heinrich",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 60.0,
      "sigma_ka": 2.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Hemming 2004",
      "source_url": "https://www.whoi.edu/cms/files/Hemming_2004_282086.pdf",
      "notes": ""
    },
    {
      "id": "gi_1_blling_allerd",
      "name": "GI-1 / Bølling-Allerød",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 14.64,
      "sigma_ka": 0.05,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_2",
      "name": "GI-2",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 23.29,
      "sigma_ka": 0.1,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_3",
      "name": "GI-3",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 27.73,
      "sigma_ka": 0.1,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_4",
      "name": "GI-4",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 28.85,
      "sigma_ka": 0.1,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_5_1",
      "name": "GI-5.1",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 30.79,
      "sigma_ka": 0.15,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Corrected during source review: 30.60 ka b2k is GS-5.1 start; GI-5.1 start is about 30.84 ka b2k, reported here as 30.79 ka BP."
    },
    {
      "id": "gi_5_2",
      "name": "GI-5.2",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 32.45,
      "sigma_ka": 0.15,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_6",
      "name": "GI-6",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 33.69,
      "sigma_ka": 0.15,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_7",
      "name": "GI-7",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 35.43,
      "sigma_ka": 0.15,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_8",
      "name": "GI-8",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 38.17,
      "sigma_ka": 0.2,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_9",
      "name": "GI-9",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 40.11,
      "sigma_ka": 0.2,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_10",
      "name": "GI-10",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 41.41,
      "sigma_ka": 0.2,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_11",
      "name": "GI-11",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 43.29,
      "sigma_ka": 0.25,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_12",
      "name": "GI-12",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 46.81,
      "sigma_ka": 0.3,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_13",
      "name": "GI-13",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 49.23,
      "sigma_ka": 0.3,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_14",
      "name": "GI-14",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 54.17,
      "sigma_ka": 0.4,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_15",
      "name": "GI-15",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 55.35,
      "sigma_ka": 0.4,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_16",
      "name": "GI-16",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 58.22,
      "sigma_ka": 0.5,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_17",
      "name": "GI-17",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 59.39,
      "sigma_ka": 0.5,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_18",
      "name": "GI-18",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 64.05,
      "sigma_ka": 0.7,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_19",
      "name": "GI-19",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 72.25,
      "sigma_ka": 0.8,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_20",
      "name": "GI-20",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 76.35,
      "sigma_ka": 1.0,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_21",
      "name": "GI-21",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 84.95,
      "sigma_ka": 1.5,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_22",
      "name": "GI-22",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 89.95,
      "sigma_ka": 1.5,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_23",
      "name": "GI-23",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 103.95,
      "sigma_ka": 2.0,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "gi_24",
      "name": "GI-24",
      "category": "dansgaard_oeschger",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 108.25,
      "sigma_ka": 2.0,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2014",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2014QSRv..106...14R/abstract",
      "notes": "Rasmussen et al. report Greenland interstadial onset ages in ka b2k; this working date is converted to ka BP by subtracting 0.05 ka."
    },
    {
      "id": "mwp_1a",
      "name": "MWP-1A",
      "category": "meltwater_pulse",
      "analysis_role": "sensitivity",
      "date_ka_bp": 14.2,
      "sigma_ka": 0.3,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Liu & Milliman 2004",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2004JOUC....3..183L/abstract",
      "notes": "Meltwater-pulse timing and labels are less uniform across sources; sensitivity catalog only."
    },
    {
      "id": "mwp_1b",
      "name": "MWP-1B",
      "category": "meltwater_pulse",
      "analysis_role": "sensitivity",
      "date_ka_bp": 11.35,
      "sigma_ka": 0.15,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Liu & Milliman 2004",
      "source_url": "https://ui.adsabs.harvard.edu/abs/2004JOUC....3..183L/abstract",
      "notes": "Meltwater-pulse timing and labels are less uniform across sources; sensitivity catalog only."
    },
    {
      "id": "mwp_1c",
      "name": "MWP-1C",
      "category": "meltwater_pulse",
      "analysis_role": "sensitivity",
      "date_ka_bp": 9.5,
      "sigma_ka": 0.5,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Stanford et al. 2011",
      "source_url": "https://doi.org/10.1016/j.gloplacha.2010.11.002",
      "notes": "Meltwater-pulse timing and labels are less uniform across sources; sensitivity catalog only."
    },
    {
      "id": "mis_1_2_end_lgm",
      "name": "MIS 1/2 (end LGM)",
      "category": "mis_boundary",
      "analysis_role": "sensitivity",
      "date_ka_bp": 14.0,
      "sigma_ka": 0.3,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Lisiecki & Raymo 2005",
      "source_url": "https://lorraine-lisiecki.com/LisieckiRaymo2005.pdf",
      "notes": ""
    },
    {
      "id": "lgm_peak",
      "name": "LGM peak",
      "category": "mis_boundary",
      "analysis_role": "sensitivity",
      "date_ka_bp": 21.0,
      "sigma_ka": 1.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Lisiecki & Raymo 2005",
      "source_url": "https://lorraine-lisiecki.com/LisieckiRaymo2005.pdf",
      "notes": ""
    },
    {
      "id": "mis_2_3",
      "name": "MIS 2/3",
      "category": "mis_boundary",
      "analysis_role": "sensitivity",
      "date_ka_bp": 29.0,
      "sigma_ka": 1.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Lisiecki & Raymo 2005",
      "source_url": "https://lorraine-lisiecki.com/LisieckiRaymo2005.pdf",
      "notes": ""
    },
    {
      "id": "mis_3_4",
      "name": "MIS 3/4",
      "category": "mis_boundary",
      "analysis_role": "sensitivity",
      "date_ka_bp": 57.0,
      "sigma_ka": 2.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Lisiecki & Raymo 2005",
      "source_url": "https://lorraine-lisiecki.com/LisieckiRaymo2005.pdf",
      "notes": ""
    },
    {
      "id": "mis_4_5",
      "name": "MIS 4/5",
      "category": "mis_boundary",
      "analysis_role": "sensitivity",
      "date_ka_bp": 71.0,
      "sigma_ka": 2.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Lisiecki & Raymo 2005",
      "source_url": "https://lorraine-lisiecki.com/LisieckiRaymo2005.pdf",
      "notes": ""
    },
    {
      "id": "mis_5d_e_eemian_peak",
      "name": "MIS 5d/e (Eemian peak)",
      "category": "mis_boundary",
      "analysis_role": "sensitivity",
      "date_ka_bp": 123.0,
      "sigma_ka": 2.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Lisiecki & Raymo 2005",
      "source_url": "https://lorraine-lisiecki.com/LisieckiRaymo2005.pdf",
      "notes": ""
    },
    {
      "id": "mis_5_6_eemian_onset",
      "name": "MIS 5/6 (Eemian onset)",
      "category": "mis_boundary",
      "analysis_role": "sensitivity",
      "date_ka_bp": 130.0,
      "sigma_ka": 2.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Lisiecki & Raymo 2005",
      "source_url": "https://lorraine-lisiecki.com/LisieckiRaymo2005.pdf",
      "notes": ""
    },
    {
      "id": "mis_6_7",
      "name": "MIS 6/7",
      "category": "mis_boundary",
      "analysis_role": "sensitivity",
      "date_ka_bp": 191.0,
      "sigma_ka": 3.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Lisiecki & Raymo 2005",
      "source_url": "https://lorraine-lisiecki.com/LisieckiRaymo2005.pdf",
      "notes": ""
    },
    {
      "id": "mis_7_8",
      "name": "MIS 7/8",
      "category": "mis_boundary",
      "analysis_role": "sensitivity",
      "date_ka_bp": 243.0,
      "sigma_ka": 3.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Lisiecki & Raymo 2005",
      "source_url": "https://lorraine-lisiecki.com/LisieckiRaymo2005.pdf",
      "notes": ""
    },
    {
      "id": "tambora",
      "name": "Tambora",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 0.135,
      "sigma_ka": 0.001,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Self et al. 2004 (VEI 7)",
      "source_url": "https://doi.org/10.1029/2004GL020925",
      "notes": ""
    },
    {
      "id": "samalas_rinjani",
      "name": "Samalas (Rinjani)",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 0.693,
      "sigma_ka": 0.003,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Lavigne 2013 (VEI 7)",
      "source_url": "https://doi.org/10.1073/pnas.1307520110",
      "notes": ""
    },
    {
      "id": "kuwae_1452",
      "name": "Kuwae 1452",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 0.498,
      "sigma_ka": 0.01,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": true,
      "source": "Gao et al. 2006 (VEI 6-7, debated)",
      "source_url": "https://doi.org/10.1029/2005JD006710",
      "notes": "Attribution and exact date are debated; exploratory only."
    },
    {
      "id": "thera_santorini",
      "name": "Thera (Santorini)",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 3.6,
      "sigma_ka": 0.05,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Friedrich 2006 (VEI 7)",
      "source_url": "https://doi.org/10.1126/science.1125087",
      "notes": ""
    },
    {
      "id": "hekla_3",
      "name": "Hekla 3",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 2.98,
      "sigma_ka": 0.02,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Larsen & Thorarinsson 1977",
      "source_url": "https://doi.org/10.33799/jokull1977.27.028",
      "notes": ""
    },
    {
      "id": "hekla_4",
      "name": "Hekla 4",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 4.26,
      "sigma_ka": 0.03,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Larsen & Thorarinsson 1977",
      "source_url": "https://doi.org/10.33799/jokull1977.27.028",
      "notes": ""
    },
    {
      "id": "hekla_5",
      "name": "Hekla 5",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 7.05,
      "sigma_ka": 0.05,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Larsen & Thorarinsson 1977",
      "source_url": "https://doi.org/10.33799/jokull1977.27.028",
      "notes": ""
    },
    {
      "id": "kikai_akahoya",
      "name": "Kikai Akahoya",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 7.3,
      "sigma_ka": 0.1,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Smith et al. 2013 (VEI 7)",
      "source_url": "https://doi.org/10.1016/j.quascirev.2013.01.026",
      "notes": ""
    },
    {
      "id": "mt_mazama_crater_lake",
      "name": "Mt. Mazama (Crater Lake)",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 7.7,
      "sigma_ka": 0.05,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Bacon 1983 (VEI 7)",
      "source_url": "https://pubs.usgs.gov/publication/70011370",
      "notes": ""
    },
    {
      "id": "mt_hudson_h1",
      "name": "Mt. Hudson H1",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 8.0,
      "sigma_ka": 0.1,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Stern 2008 (VEI 6)",
      "source_url": "https://doi.org/10.1007/s00445-007-0148-z",
      "notes": ""
    },
    {
      "id": "cerro_hudson",
      "name": "Cerro Hudson",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 6.7,
      "sigma_ka": 0.1,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Naranjo 1991 (VEI 6)",
      "source_url": "https://www.andeangeology.cl/index.php/revista1/article/view/2494/0",
      "notes": ""
    },
    {
      "id": "laacher_see",
      "name": "Laacher See",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 12.9,
      "sigma_ka": 0.2,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Reinig et al. 2021 (VEI 6)",
      "source_url": "https://doi.org/10.1038/s41586-021-03608-x",
      "notes": ""
    },
    {
      "id": "oruanui_taupo",
      "name": "Oruanui (Taupō)",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 25.4,
      "sigma_ka": 0.3,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Vandergoes 2013 (VEI 8)",
      "source_url": "https://doi.org/10.1016/j.quascirev.2012.11.006",
      "notes": ""
    },
    {
      "id": "aira_ito",
      "name": "Aira (Ito)",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 30.0,
      "sigma_ka": 0.5,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Smith et al. 2013 (VEI 7)",
      "source_url": "https://doi.org/10.1016/j.quascirev.2013.01.026",
      "notes": ""
    },
    {
      "id": "campanian_ignimbrite",
      "name": "Campanian Ignimbrite",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 39.85,
      "sigma_ka": 0.14,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "De Vivo 2001 (VEI 7)",
      "source_url": "https://doi.org/10.1007/s007100170010",
      "notes": ""
    },
    {
      "id": "rotoiti",
      "name": "Rotoiti",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 50.0,
      "sigma_ka": 1.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Wilson 2007 (VEI 6)",
      "source_url": "https://doi.org/10.1016/j.quascirev.2007.04.017",
      "notes": ""
    },
    {
      "id": "toba",
      "name": "Toba",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 74.0,
      "sigma_ka": 2.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Storey 2012 (VEI 8)",
      "source_url": "https://doi.org/10.1073/pnas.1208178109",
      "notes": ""
    },
    {
      "id": "atitlan_los_chocoyos",
      "name": "Atitlán (Los Chocoyos)",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 84.0,
      "sigma_ka": 3.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Drexler 1980 (VEI 7+)",
      "source_url": "https://doi.org/10.1016/0033-5894(80)90061-7",
      "notes": ""
    },
    {
      "id": "aso_4",
      "name": "Aso-4",
      "category": "volcanic",
      "analysis_role": "exploratory",
      "date_ka_bp": 87.0,
      "sigma_ka": 3.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Aoki 2008 (VEI 7+)",
      "source_url": "https://doi.org/10.1016/j.quaint.2007.02.005",
      "notes": ""
    },
    {
      "id": "kaali_estonia",
      "name": "Kaali (Estonia)",
      "category": "impact",
      "analysis_role": "exploratory",
      "date_ka_bp": 3.5,
      "sigma_ka": 0.5,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Veski 2001",
      "source_url": "https://doi.org/10.1111/j.1945-5100.2001.tb01830.x",
      "notes": "Kaali age estimates vary across studies; exploratory only."
    },
    {
      "id": "henbury_australia",
      "name": "Henbury (Australia)",
      "category": "impact",
      "analysis_role": "exploratory",
      "date_ka_bp": 4.2,
      "sigma_ka": 1.9,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Earth Impact DB",
      "source_url": "https://impact.uwo.ca/",
      "notes": ""
    },
    {
      "id": "campo_del_cielo_argentina",
      "name": "Campo del Cielo (Argentina)",
      "category": "impact",
      "analysis_role": "exploratory",
      "date_ka_bp": 4.5,
      "sigma_ka": 1.5,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Cassidy 1965",
      "source_url": "https://doi.org/10.1126/science.149.3688.1055",
      "notes": ""
    },
    {
      "id": "macha_russia",
      "name": "Macha (Russia)",
      "category": "impact",
      "analysis_role": "exploratory",
      "date_ka_bp": 7.3,
      "sigma_ka": 0.5,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Earth Impact DB",
      "source_url": "https://impact.uwo.ca/",
      "notes": ""
    },
    {
      "id": "ydih_younger_dryas",
      "name": "YDIH (Younger Dryas)",
      "category": "impact",
      "analysis_role": "exploratory",
      "date_ka_bp": 12.8,
      "sigma_ka": 0.2,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": true,
      "source": "Firestone 2007; Moore 2017 (disputed)",
      "source_url": "https://doi.org/10.1073/pnas.0706977104",
      "notes": "Moore et al. 2017 platinum anomaly paper: https://doi.org/10.1038/srep44031. The impact interpretation remains disputed."
    },
    {
      "id": "tenoumer_mauritania",
      "name": "Tenoumer (Mauritania)",
      "category": "impact",
      "analysis_role": "exploratory",
      "date_ka_bp": 21.4,
      "sigma_ka": 9.7,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Earth Impact DB",
      "source_url": "https://impact.uwo.ca/",
      "notes": ""
    },
    {
      "id": "barringer_meteor_usa",
      "name": "Barringer/Meteor (USA)",
      "category": "impact",
      "analysis_role": "exploratory",
      "date_ka_bp": 50.0,
      "sigma_ka": 3.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Phillips 1991",
      "source_url": "https://doi.org/10.1016/0016-7037(91)90387-K",
      "notes": ""
    },
    {
      "id": "lonar_india",
      "name": "Lonar (India)",
      "category": "impact",
      "analysis_role": "exploratory",
      "date_ka_bp": 570.0,
      "sigma_ka": 47.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Jourdan 2011 (Ar/Ar redating)",
      "source_url": "https://doi.org/10.1130/G31888.1",
      "notes": "Lonar age remains debated; later cosmogenic-nuclide work proposed a much younger age than the Ar/Ar date used here. Outside dashboard window either way."
    },
    {
      "id": "rockall_excursion",
      "name": "Rockall excursion",
      "category": "geomagnetic",
      "analysis_role": "exploratory",
      "date_ka_bp": 26.0,
      "sigma_ka": 1.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Channell 2016",
      "source_url": "https://doi.org/10.1002/2016GC006300",
      "notes": "Source label corrected during source review: the Rockall Trough excursion is Channell et al. 2016, not the 2014 Iceland Basin paper."
    },
    {
      "id": "mono_lake_excursion",
      "name": "Mono Lake excursion",
      "category": "geomagnetic",
      "analysis_role": "exploratory",
      "date_ka_bp": 33.5,
      "sigma_ka": 1.5,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Liu et al. 2018, 2024",
      "source_url": "https://doi.org/10.1016/j.epsl.2018.12.029",
      "notes": ""
    },
    {
      "id": "laschamps_excursion",
      "name": "Laschamps excursion",
      "category": "geomagnetic",
      "analysis_role": "exploratory",
      "date_ka_bp": 41.0,
      "sigma_ka": 0.4,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Lascu 2016; Singer 2009",
      "source_url": "https://doi.org/10.1029/2011GC004017",
      "notes": ""
    },
    {
      "id": "norwegian_greenland_sea",
      "name": "Norwegian-Greenland Sea",
      "category": "geomagnetic",
      "analysis_role": "exploratory",
      "date_ka_bp": 65.0,
      "sigma_ka": 5.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Channell 2020",
      "source_url": "https://doi.org/10.1016/j.quascirev.2019.106114",
      "notes": "Channell et al. 2020 discusses concerns about some Norwegian-Greenland Sea excursion records; exploratory only."
    },
    {
      "id": "blake_excursion",
      "name": "Blake excursion",
      "category": "geomagnetic",
      "analysis_role": "exploratory",
      "date_ka_bp": 117.0,
      "sigma_ka": 5.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Singer 2014 GITS",
      "source_url": "https://doi.org/10.1016/j.epsl.2007.12.009",
      "notes": "Source URL points to Singer and Jicha 2008 supporting the geomagnetic instability time scale used by Singer 2014; exploratory only."
    },
    {
      "id": "iceland_basin",
      "name": "Iceland Basin",
      "category": "geomagnetic",
      "analysis_role": "exploratory",
      "date_ka_bp": 190.0,
      "sigma_ka": 5.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Channell 2020",
      "source_url": "https://doi.org/10.1016/j.quascirev.2019.106114",
      "notes": ""
    },
    {
      "id": "pringle_falls",
      "name": "Pringle Falls",
      "category": "geomagnetic",
      "analysis_role": "exploratory",
      "date_ka_bp": 220.0,
      "sigma_ka": 15.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Singer 2014 GITS",
      "source_url": "https://doi.org/10.1016/j.epsl.2007.12.009",
      "notes": "Source URL points to Singer and Jicha 2008 supporting the geomagnetic instability time scale used by Singer 2014; exploratory only."
    },
    {
      "id": "miyake_774_ce",
      "name": "Miyake 774 CE",
      "category": "solar_particle",
      "analysis_role": "exploratory",
      "date_ka_bp": 1.176,
      "sigma_ka": 0.0001,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": 774,
      "contested": false,
      "source": "Miyake 2012",
      "source_url": "https://doi.org/10.1038/nature11123",
      "notes": "Corrected from an earlier factor-1000 ka BP encoding. 774 CE is about 1.176 ka before 1950 CE."
    },
    {
      "id": "miyake_993_ce",
      "name": "Miyake 993 CE",
      "category": "solar_particle",
      "analysis_role": "exploratory",
      "date_ka_bp": 0.957,
      "sigma_ka": 0.0001,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": 993,
      "contested": false,
      "source": "Miyake 2013",
      "source_url": "https://doi.org/10.1038/ncomms2783",
      "notes": "Corrected from an earlier factor-1000 ka BP encoding. 993 CE is about 0.957 ka before 1950 CE."
    },
    {
      "id": "miyake_660_bce",
      "name": "Miyake 660 BCE",
      "category": "solar_particle",
      "analysis_role": "exploratory",
      "date_ka_bp": 2.613,
      "sigma_ka": 0.002,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": -660,
      "contested": false,
      "source": "Park 2017; 2024",
      "source_url": "https://doi.org/10.1017/RDC.2017.59",
      "notes": "Later timing refinement: https://doi.org/10.1038/s43247-024-01618-x."
    },
    {
      "id": "miyake_5259_bce",
      "name": "Miyake 5259 BCE",
      "category": "solar_particle",
      "analysis_role": "exploratory",
      "date_ka_bp": 7.209,
      "sigma_ka": 0.005,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": -5259,
      "contested": false,
      "source": "Brehm 2022",
      "source_url": "https://doi.org/10.1038/s41467-022-28804-9",
      "notes": ""
    },
    {
      "id": "miyake_5410_bce",
      "name": "Miyake 5410 BCE",
      "category": "solar_particle",
      "analysis_role": "exploratory",
      "date_ka_bp": 7.36,
      "sigma_ka": 0.01,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": -5410,
      "contested": false,
      "source": "Miyake 2021 (smaller)",
      "source_url": "https://doi.org/10.1029/2021GL093419",
      "notes": ""
    },
    {
      "id": "miyake_7176_bce",
      "name": "Miyake 7176 BCE",
      "category": "solar_particle",
      "analysis_role": "exploratory",
      "date_ka_bp": 9.126,
      "sigma_ka": 0.005,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": -7176,
      "contested": false,
      "source": "Brehm 2022",
      "source_url": "https://doi.org/10.1038/s41467-022-28804-9",
      "notes": ""
    },
    {
      "id": "miyake_12350_bce",
      "name": "Miyake 12350 BCE",
      "category": "solar_particle",
      "analysis_role": "exploratory",
      "date_ka_bp": 14.3,
      "sigma_ka": 0.05,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": -12350,
      "contested": false,
      "source": "Bard et al. 2023 (largest known)",
      "source_url": "https://doi.org/10.1098/rsta.2022.0206",
      "notes": "Source review: the primary paper is Bard et al. 2023; Bayliss is a coauthor."
    },
    {
      "id": "8_2_ka_event",
      "name": "8.2 ka event",
      "category": "holocene_climate",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 8.2,
      "sigma_ka": 0.05,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Alley 1997",
      "source_url": "https://pure.psu.edu/en/publications/holocene-climatic-instability-a-prominent-widespread-event-8200-y/",
      "notes": "Renamed during source review to avoid conflating the 8.2 ka climate event with the separate Storegga slide and tsunami."
    },
    {
      "id": "5_9_ka_event_sahara_dry",
      "name": "5.9 ka event (Sahara dry)",
      "category": "holocene_climate",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 5.9,
      "sigma_ka": 0.2,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "deMenocal 2000",
      "source_url": "https://www.sciencedirect.com/science/article/pii/S0277379199000815",
      "notes": ""
    },
    {
      "id": "4_2_ka_event",
      "name": "4.2 ka event",
      "category": "holocene_climate",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 4.2,
      "sigma_ka": 0.2,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Weiss 1993",
      "source_url": "https://pubmed.ncbi.nlm.nih.gov/17739617/",
      "notes": ""
    },
    {
      "id": "late_bronze_age_cold_3_2_ka",
      "name": "Late Bronze Age cold (3.2 ka)",
      "category": "holocene_climate",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 3.2,
      "sigma_ka": 0.2,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Kaniewski 2013",
      "source_url": "https://pubmed.ncbi.nlm.nih.gov/23967146/",
      "notes": ""
    },
    {
      "id": "little_ice_age_onset",
      "name": "Little Ice Age onset",
      "category": "holocene_climate",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 0.7,
      "sigma_ka": 0.1,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Mann 2009",
      "source_url": "https://doi.org/10.1126/science.1177303",
      "notes": ""
    },
    {
      "id": "medieval_warm_period",
      "name": "Medieval Warm Period",
      "category": "holocene_climate",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 1.0,
      "sigma_ka": 0.2,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Mann 2009",
      "source_url": "https://doi.org/10.1126/science.1177303",
      "notes": ""
    },
    {
      "id": "yd_onset",
      "name": "YD onset",
      "category": "holocene_climate",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 12.846,
      "sigma_ka": 0.1,
      "date_basis": "onset_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2006",
      "source_url": "https://doi.org/10.1029/2005JD006079",
      "notes": "Rasmussen 2006 reports about 12.896 ka b2k; converted here to 12.846 ka BP."
    },
    {
      "id": "yd_termination",
      "name": "YD termination",
      "category": "holocene_climate",
      "analysis_role": "primary_paleoclimate",
      "date_ka_bp": 11.653,
      "sigma_ka": 0.05,
      "date_basis": "termination_ka_before_1950_converted_from_b2k",
      "calendar_year": null,
      "contested": false,
      "source": "Rasmussen 2006",
      "source_url": "https://doi.org/10.1029/2005JD006079",
      "notes": "Rasmussen 2006 reports about 11.703 ka b2k; converted here to 11.653 ka BP."
    },
    {
      "id": "australia_megafauna_lad",
      "name": "Australia megafauna LAD",
      "category": "megafauna",
      "analysis_role": "exploratory",
      "date_ka_bp": 46.0,
      "sigma_ka": 2.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Roberts 2001",
      "source_url": "https://doi.org/10.1126/science.1060264",
      "notes": ""
    },
    {
      "id": "north_america_megafauna_lad",
      "name": "North America megafauna LAD",
      "category": "megafauna",
      "analysis_role": "exploratory",
      "date_ka_bp": 11.0,
      "sigma_ka": 0.5,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Faith & Surovell 2009",
      "source_url": "https://doi.org/10.1073/pnas.0908153106",
      "notes": ""
    },
    {
      "id": "south_america_megafauna_lad",
      "name": "South America megafauna LAD",
      "category": "megafauna",
      "analysis_role": "exploratory",
      "date_ka_bp": 10.5,
      "sigma_ka": 0.5,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Barnosky & Lindsey 2010",
      "source_url": "https://doi.org/10.1016/j.quaint.2009.11.017",
      "notes": ""
    },
    {
      "id": "eurasian_woolly_mammoth_mainland",
      "name": "Eurasian woolly mammoth (mainland)",
      "category": "megafauna",
      "analysis_role": "exploratory",
      "date_ka_bp": 10.0,
      "sigma_ka": 1.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Stuart 2015",
      "source_url": "https://doi.org/10.1002/gj.2633",
      "notes": ""
    },
    {
      "id": "wrangel_island_mammoth_lad",
      "name": "Wrangel Island mammoth LAD",
      "category": "megafauna",
      "analysis_role": "exploratory",
      "date_ka_bp": 4.0,
      "sigma_ka": 0.1,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Vartanyan 1995",
      "source_url": "https://www.cambridge.org/core/journals/radiocarbon/article/radiocarbon-dating-evidence-for-mammoths-on-wrangel-island-arctic-ocean-until-2000-bc1/B24BB69C26D3B36B7A6FC1CB1EE1AAD5",
      "notes": ""
    },
    {
      "id": "caribbean_ground_sloth_lad",
      "name": "Caribbean ground sloth LAD",
      "category": "megafauna",
      "analysis_role": "exploratory",
      "date_ka_bp": 4.4,
      "sigma_ka": 0.1,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "MacPhee 2005",
      "source_url": "https://doi.org/10.1073/pnas.0502777102",
      "notes": ""
    },
    {
      "id": "gobekli_tepe_construction",
      "name": "Göbekli Tepe construction",
      "category": "cultural",
      "analysis_role": "exploratory",
      "date_ka_bp": 10.7,
      "sigma_ka": 0.5,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Schmidt 2010, AMS 14C",
      "source_url": "https://doi.org/10.4312/dp.37.21",
      "notes": "Schmidt 2010 is an archaeological source; the AMS radiocarbon note cited in the source label appears separately and is not the DOI target here."
    },
    {
      "id": "out_of_africa_wave_2",
      "name": "Out-of-Africa wave 2",
      "category": "cultural",
      "analysis_role": "exploratory",
      "date_ka_bp": 60.0,
      "sigma_ka": 10.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Mellars 2006",
      "source_url": "https://doi.org/10.1126/science.1128402",
      "notes": ""
    },
    {
      "id": "australia_first_arrival",
      "name": "Australia first arrival",
      "category": "cultural",
      "analysis_role": "exploratory",
      "date_ka_bp": 65.0,
      "sigma_ka": 5.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Clarkson 2017",
      "source_url": "https://doi.org/10.1038/nature22968",
      "notes": ""
    },
    {
      "id": "americas_first_arrival",
      "name": "Americas first arrival",
      "category": "cultural",
      "analysis_role": "exploratory",
      "date_ka_bp": 17.0,
      "sigma_ka": 3.0,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Bennett 2021 (White Sands)",
      "source_url": "https://doi.org/10.1126/science.abg7586",
      "notes": ""
    },
    {
      "id": "neolithic_agriculture",
      "name": "Neolithic agriculture",
      "category": "cultural",
      "analysis_role": "exploratory",
      "date_ka_bp": 11.5,
      "sigma_ka": 0.5,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Zeder 2011",
      "source_url": "https://doi.org/10.1086/659307",
      "notes": ""
    },
    {
      "id": "end_of_last_glacial",
      "name": "End of Last Glacial",
      "category": "cultural",
      "analysis_role": "exploratory",
      "date_ka_bp": 11.7,
      "sigma_ka": 0.05,
      "date_basis": "midpoint_ka_before_1950",
      "calendar_year": null,
      "contested": false,
      "source": "Walker 2009 (formal definition)",
      "source_url": "https://doi.org/10.1002/jqs.1227",
      "notes": ""
    }
  ]
}