{
 "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": "Sandwich", "series": "Plates", "artist": "Kenny Lienhard", "year": 2026, "plate": "41 of 52", "palette": "obsidian"},
 "plate": {"name": "Sandwich", "code": "SW", "model": "PB2002 (Bird 2003)", "class": "micro", "area_km2": 184414, "centroid_lat_lon": [-57.801, -27.374], "ocean_share": 0.9984, "land_share": 0.0016},
 "motion": {"frame": "no-net-rotation", "euler_pole_lat_lon": [-38.1382, -33.609], "rotation_deg_per_million_years": 1.90941, "speed_mm_per_year_at_centroid": 72.9, "heading_deg_at_centroid": 75.6, "speed_range_mm_per_year": [62.51, 82.22], "the_artwork_drifts": "72.9 mm a year along its cut, one frame of rock every 12999 years"},
 "cover": {"deep ocean": 0.4759, "slope and ridge": 0.447, "ocean trench": 0.0719, "shelf sea": 0.0036, "ice": 0.0015},
 "palette_from": ["deep ocean", "ocean", "ocean trench"],
 "era": null,
 "past": {"account": "The past. At the ice age peak, around 20,000 years ago, winter sea ice spread far north of these islands, to about 48 degrees south, and covered the whole plate each winter, where today it covers about three quarters of it. Ice that lasted through the summer may have reached the plate’s southern edge, but the records disagree on how far. The islands are steep volcanoes, so even with the sea more than 100 metres lower they gained only about 200 square kilometres of land, and their ice caps likely stayed close to today’s extent.", "source": "Lhardy et al. 2021, Climate of the Past 17:1139; Green et al. 2022, Climate of the Past 18:845; Hodgson et al. 2014, Quaternary Science Reviews 100:137; Lambeck et al. 2014, PNAS 111:15296; NSIDC Sea Ice Index v4; ETOPO 2022"},
 "history": [{"years_ago": 15000000, "range_years_ago": [15750000, 14250000], "what": "Back-arc spreading began behind the South Sandwich arc, at least by this time.", "source": "Larter et al. 2003, Geological Society London Special Publications 219:255, doi:10.1144/GSL.SP.2003.219.01.13"}, {"years_ago": 10000000, "range_years_ago": [10500000, 9500000], "what": "The crust beneath this plate's volcanic arc began to form at the back-arc ridge.", "source": "Larter et al. 2003, Geological Society London Special Publications 219:255, doi:10.1144/GSL.SP.2003.219.01.13"}],
 "outline_lon_lat": [[[-28.65, -55.0], [-29.49, -55.03], [-29.71, -55.2], [-29.81, -55.33], [-29.79, -55.5], [-29.77, -55.6], [-29.82, -55.68], [-30.32, -55.75], [-30.33, -55.86], [-30.33, -55.95], [-30.33, -56.05], [-30.33, -56.13], [-30.33, -56.29], [-30.38, -56.44], [-30.72, -56.45], [-30.73, -56.51], [-30.74, -56.57], [-30.74, -56.86], [-30.47, -56.85], [-30.38, -57.09], [-30.13, -57.1], [-30.07, -57.6], [-29.85, -57.6], [-29.84, -58.26], [-30.01, -58.27], [-29.95, -58.81], [-29.56, -58.82], [-29.55, -59.51], [-30.11, -59.52], [-30.03, -59.94], [-29.88, -60.17], [-29.6, -60.43], [-28.68, -60.46], [-27.7, -60.47], [-27.7, -60.62], [-26.89, -60.51], [-26.07, -60.39], [-25.07, -59.97], [-24.46, -59.39], [-23.99, -58.92], [-23.82, -58.2], [-24.13, -57.43], [-24.23, -57.17], [-24.7, -56.73], [-25.15, -56.29], [-25.72, -55.84], [-26.41, -55.42], [-26.99, -55.23], [-27.6, -55.09], [-28.65, -55.0]]],
 "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"
}