{
 "about": "The record of this Plate: the facts it is drawn from, kept inside the work. Plain JSON; the artwork does not read it. CC0 1.0, no rights reserved.",
 "work": {"title": "Mariana", "series": "Plates", "artist": "Kenny Lienhard", "year": 2026, "plate": "30 of 52", "palette": "rhyolite"},
 "plate": {"name": "Mariana", "code": "MA", "model": "PB2002 (Bird 2003)", "class": "micro", "area_km2": 420799, "centroid_lat_lon": [17.877, 145.442], "ocean_share": 0.9975, "land_share": 0.0025},
 "motion": {"frame": "no-net-rotation", "euler_pole_lat_lon": [14.7392, 139.5731], "rotation_deg_per_million_years": 1.19737, "speed_mm_per_year_at_centroid": 14.95, "heading_deg_at_centroid": 331.7, "speed_range_mm_per_year": [9.8, 23.9], "the_artwork_drifts": "-14.95 mm a year along its cut, one frame of rock every 23655 years"},
 "cover": {"deep ocean": 0.601, "slope and ridge": 0.2747, "ocean trench": 0.1193, "shelf sea": 0.0026, "grassland": 0.0016, "cropland": 0.0007, "rainforest": 0.0002},
 "palette_from": ["deep ocean", "ocean", "ocean trench"],
 "era": null,
 "past": {"account": "The past. At the ice age peak the sea stood more than 120 metres lower, and the Mariana Islands were about half as large again as today, Guam a quarter larger and Saipan about twice its size, yet no two of the main islands ever joined. The rising sea took that land back, mostly between about 16,000 and 7,000 years ago. People first reached the islands some 3,200 to 3,500 years ago, across more than 2,000 kilometres of open ocean, and by about 2,400 years ago their fires had turned the upland forests of southern Guam into the savanna seen today.", "source": "Lambeck et al. 2014, PNAS 111:15296; Norder et al. 2018, Global Ecology and Biogeography 27:500; Rieth and Athens 2019, Journal of Island and Coastal Archaeology 14:5; Pugach et al. 2021, PNAS 118:e2022112118; Athens and Ward 2004, Records of the Australian Museum Supplement 29:15"},
 "history": [{"years_ago": 6000000, "range_years_ago": [6300000, 5700000], "what": "The Mariana Trough began to open behind the arc, splitting this plate from the Philippine Sea plate.", "source": "Taylor 1992, Proceedings ODP Scientific Results 126:627-651, doi:10.2973/odp.proc.sr.126.163.1992"}],
 "outline_lon_lat": [[[143.11, 12.03], [143.08, 11.79], [143.1, 11.57], [143.5, 11.49], [144.16, 11.79], [144.62, 12.02], [145.02, 12.21], [145.35, 12.31], [145.69, 12.65], [146.22, 13.0], [146.75, 13.36], [147.2, 14.22], [147.46, 14.97], [147.68, 15.65], [147.79, 16.52], [147.86, 17.28], [147.81, 18.06], [147.82, 18.65], [147.62, 19.17], [147.46, 19.75], [147.21, 20.3], [146.82, 21.33], [146.54, 21.73], [146.06, 22.2], [145.29, 22.71], [144.71, 23.25], [144.02, 23.76], [143.52, 24.39], [142.89, 23.7], [142.26, 23.01], [142.56, 22.66], [142.77, 22.38], [143.0, 22.14], [143.15, 21.93], [143.22, 21.66], [143.28, 21.32], [143.32, 21.06], [143.28, 20.96], [143.39, 20.73], [143.49, 20.53], [143.57, 20.4], [143.84, 20.42], [143.97, 20.11], [144.08, 19.86], [144.14, 19.75], [144.25, 19.73], [144.53, 19.12], [144.54, 19.07], [144.6, 18.76], [144.63, 18.36], [144.66, 18.17], [144.71, 18.02], [144.77, 17.83], [144.97, 17.53], [144.67, 17.42], [144.8, 16.98], [144.84, 16.48], [144.79, 16.12], [144.8, 15.65], [144.45, 15.53], [144.53, 14.92], [144.33, 14.88], [144.22, 14.66], [144.08, 14.64], [143.98, 14.09], [143.94, 13.81], [143.9, 13.62], [143.87, 13.54], [143.77, 13.27], [143.66, 13.06], [143.51, 12.82], [143.4, 12.69], [143.24, 12.48], [143.14, 12.27], [143.11, 12.03]]],
 "sources": ["Plate outlines and motion: Bird, P. (2003). An updated digital model of plate boundaries. Geochemistry, Geophysics, Geosystems 4(3), 1027, doi:10.1029/2001GC000252. No-net-rotation frame computed from PB2002 alone.", "What covers each plate: ESA CCI Land Cover and Water Bodies, NOAA ETOPO 2022, Koppen-Geiger climate maps, NSIDC Sea Ice Index, on a 1 arc-minute grid."],
 "engine_sha256": "a7fbc03acc0fc9ba343881bb88ddaf2b7564564d8bc9cbed16e75e47e01fb3f2"
}