The Avalon 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.
78° on Nov. 11, 2020, the hottest reading for this week of the year since 1991. Next is 73° in 2014.
Avalon’s center stands about 920 ft above sea level. Within three miles the land runs from 690 ft to 1,230 ft, a difference of 540 ft: hilly country. The highest named summit within 15 miles is Rich Hill, about 1,290 ft, 13 miles east-northeast.
Under the town center the state geologic map shows Glenshaw Formation (shale), from the Carboniferous, 299 to 324 million years old.
The section below crosses 4 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 32×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Shale, clastic. Age: Carboniferous, 299 to 324 million years old. About 10 mi of the line.
Shale. Age: Carboniferous, 299 to 324 million years old. About 7 mi of the line.
Limestone, shale, sandstone. Age: Carboniferous, 299 to 324 million years old. About 6 mi of the line.
Sandstone, shale. Age: Carboniferous to Permian, 252 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.
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 Avalon reaches the Gulf of America by way of the Ohio and the Mississippi: about 1,940 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 Avalon; river miles along the main stem, rounded.
Avalon has a hot-summer humid continental climate. Summer afternoons average 86° in July; winter nights fall to about 21° in January. About 38 inches of rain fall in a normal year.
On November 14 Avalon normally reaches 54° and falls to 33°. The record high is 70°, in 1994; the record low 16°, in 2019. The most rain on this date, 1.10 in, fell in 1997.
Normals 1991–2020 and records since 1991 at Emsworth L/D Ohio River, here, 200 ft lower. NOAA, through RCC-ACIS.