The Triadelphia plate. Relief from Copernicus GLO-30; rivers and lakes from USGS NHD; watersheds from the USGS Watershed Boundary Dataset; roads and city limits from Census TIGER 2024.
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79° on Nov. 11, 2020, the hottest reading for this week of the year since 1987. Next is 75° in 1998.
Triadelphia’s center stands about 770 ft above sea level. Within three miles the land runs from 690 ft to 1,320 ft, a difference of 630 ft: hilly country. The highest named summit within 15 miles is Mosier Hill, about 1,510 ft, 13 miles east-northeast.
Under the town center the state geologic map shows Monongahela Group (sandstone, siltstone, shale), from the Carboniferous, 299 to 324 million years old.
The section below crosses 7 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 23×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Sandstone, siltstone, shale. Age: Carboniferous to Permian, 252 to 324 million years old. About 7 mi of the line.
Sandstone, shale. Age: Permian, 252 to 299 million years old. About 6 mi of the line.
Mudstone, shale, siltstone. Age: Carboniferous to Permian, 252 to 324 million years old. About 6 mi of the line.
Sandstone, siltstone, shale. Age: Carboniferous, 299 to 324 million years old. About 3 mi of the line.
Fine-detrital, coarse-detrital. Age: Quaternary, less than 2.6 million years old. About 1 mi of the line.
Shale, siltstone, mudstone. Age: Carboniferous, 299 to 324 million years old. About 0.9 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 1 smaller unit along the line are not listed.
Heights from Copernicus GLO-90 (a surface model: it includes buildings and tree canopy); summits from USGS GNIS; rivers from USGS NHDPlus HR; rock from the USGS State Geologic Map Compilation.
A raindrop that lands in Triadelphia reaches the Gulf of America by way of Middle Wheeling Creek, Wheeling Creek, the Ohio and the Mississippi: about 1,860 river miles.
970 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Triadelphia; river miles along the main stem, rounded.
Triadelphia has a hot-summer humid continental climate. Summer afternoons average 85° in July; winter nights fall to about 22° in January. About 42 inches of rain fall in a normal year.
On November 14 Triadelphia normally reaches 54° and falls to 34°. The record high is 74°, in 1989; the record low 17°, in 2019. The most rain on this date, 1.10 in, fell in 1997.
Normals 1991–2020 and records since 1987 at Wheeling, 5 miles west, 120 ft lower. NOAA, through RCC-ACIS.
