{
 "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": "Tonga", "series": "Plates", "artist": "Kenny Lienhard", "year": 2026, "plate": "39 of 52", "palette": "rhyolite"},
 "plate": {"name": "Tonga", "code": "TO", "model": "PB2002 (Bird 2003)", "class": "micro", "area_km2": 253621, "centroid_lat_lon": [-19.482, -174.432], "ocean_share": 0.9973, "land_share": 0.0027},
 "motion": {"frame": "no-net-rotation", "euler_pole_lat_lon": [25.7858, 4.2625], "rotation_deg_per_million_years": 8.96937, "speed_mm_per_year_at_centroid": 111.48, "heading_deg_at_centroid": 100.6, "speed_range_mm_per_year": [33.07, 197.35], "the_artwork_drifts": "111.48 mm a year along its cut, one frame of rock every 10000 years"},
 "cover": {"slope and ridge": 0.669, "deep ocean": 0.2211, "ocean trench": 0.0774, "shelf sea": 0.0297, "cropland": 0.0012, "rainforest": 0.001, "lakes and rivers": 0.0003, "grassland": 0.0002},
 "palette_from": ["ocean", "deep ocean", "ocean trench"],
 "era": {"name": "Low seas", "what": "Low seas, Tonga’s reefs dry land", "arrives_years_before_2026": [30100, 30000], "leaves_years_before_2026": [15386, 8266], "account": "The past. With the sea about 120 metres lower, about 5,400 square kilometres of Tonga’s reef platforms were dry land, where the plate has about 700 today: the reefs of Ha’apai made two limestone islands of about 2,200 and 1,250 square kilometres, around Nomuka and around Lifuka, and Tongatapu and Vava’u were five to eight times their present size. The land was already dry when the timeline begins; the rising sea drowned most of it between 15,386 and 8,266 years ago. The lavender line turns a little toward the colour of land, all at once, and only across those spans.", "source": "Lambeck et al. 2014, PNAS 111:15296; Dickinson and Burley 2007, Geoarchaeology 22:229; Ryan et al. 2009, Geochemistry Geophysics Geosystems 10:Q03014"},
 "history": [{"years_ago": 5500000, "range_years_ago": [5775000, 5225000], "what": "The Lau Basin began to open behind the Tonga arc.", "source": "Ruellan et al. 2003, Geochemistry Geophysics Geosystems 4, doi:10.1029/2001GC000261"}],
 "outline_lon_lat": [[[-176.36, -23.95], [-175.69, -23.85], [-174.99, -23.75], [-174.84, -23.51], [-174.66, -23.22], [-174.49, -22.91], [-174.32, -22.62], [-174.14, -22.29], [-173.95, -21.92], [-173.82, -21.53], [-173.7, -21.25], [-173.55, -20.89], [-173.4, -20.59], [-173.22, -20.2], [-173.05, -19.78], [-172.97, -19.46], [-172.87, -19.07], [-172.7, -18.48], [-172.59, -18.15], [-172.54, -17.93], [-172.44, -17.68], [-172.37, -17.27], [-172.34, -16.96], [-172.31, -16.72], [-172.31, -16.33], [-172.3, -16.04], [-172.33, -15.73], [-172.35, -15.56], [-172.43, -15.37], [-172.6, -15.15], [-172.77, -15.03], [-172.94, -14.87], [-173.13, -14.78], [-173.27, -14.7], [-173.41, -14.58], [-173.84, -14.53], [-173.91, -14.63], [-174.01, -14.77], [-174.08, -14.89], [-174.14, -15.02], [-174.19, -15.13], [-174.26, -15.31], [-174.57, -15.25], [-174.67, -15.37], [-174.73, -15.47], [-174.82, -15.62], [-174.87, -15.74], [-174.87, -15.88], [-174.6, -15.94], [-174.57, -16.05], [-174.57, -16.2], [-174.58, -16.35], [-174.53, -16.74], [-174.53, -16.87], [-174.52, -17.07], [-174.56, -17.1], [-174.6, -17.32], [-174.57, -17.36], [-174.6, -17.61], [-174.56, -17.63], [-174.57, -17.84], [-174.66, -18.04], [-174.76, -18.23], [-174.87, -18.42], [-174.96, -18.6], [-175.03, -18.79], [-175.09, -19.0], [-175.16, -19.23], [-175.19, -19.46], [-175.21, -19.7], [-175.98, -19.39], [-176.03, -19.65], [-176.08, -19.81], [-176.12, -19.88], [-176.18, -20.11], [-176.12, -20.13], [-176.15, -20.26], [-176.16, -20.42], [-176.18, -20.49], [-176.19, -20.66], [-176.24, -20.8], [-176.26, -20.89], [-176.29, -21.0], [-176.32, -21.11], [-176.37, -21.3], [-176.41, -21.49], [-176.45, -21.6], [-176.52, -21.81], [-176.6, -22.01], [-176.63, -22.23], [-176.69, -22.29], [-176.71, -22.5], [-176.75, -22.73], [-176.91, -23.05], [-177.1, -23.41], [-177.25, -23.71], [-177.42, -24.11], [-176.89, -24.03], [-176.36, -23.95]]],
 "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"
}