The Emerson 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.
82° on Nov. 14, 1999, the hottest reading for this week of the year since 1897. Next is 76° in 1964.
Emerson’s center stands about 1,080 ft above sea level. Within three miles the land runs from 1,030 ft to 1,210 ft, a difference of 180 ft: gently rolling country.
Under the town center the state geologic map shows Shawnee Group (limestone, shale), from the Late Pennsylvanian, 299 to 307 million years old.
The section below crosses 5 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 63×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Limestone, shale. Age: Late Pennsylvanian, 299 to 307 million years old. About 10 mi of the line.
Shale, mudstone. Age: Late Pennsylvanian, 299 to 307 million years old. About 9 mi of the line.
Shale, mudstone. Age: Late Pennsylvanian, 299 to 307 million years old. About 4 mi of the line.
Sandstone, shale. Age: Early Cretaceous to Late Cretaceous, 94 to 113 million years old. About 0.9 mi of the line.
Limestone, shale. Age: Late Pennsylvanian, 299 to 307 million years old. About 0.5 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 Emerson reaches the Gulf of America by way of Indian Creek, the West Nishnabotna, the Nishnabotna, the Missouri and the Mississippi: about 1,750 river miles.
1,170 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Emerson; river miles along the main stem, rounded.
Emerson has a hot-summer humid continental climate. Summer afternoons average 86° in July; winter nights fall to about 12° in January. A normal year brings about 27 inches of snow; with the rain, that comes to about 37 inches of water.
On November 14 Emerson normally reaches 51° and falls to 28°. The record high is 82°, in 1999; the record low −1°, in 1940. The most rain on this date, 0.93 in, fell in 1902.
Normals 1991–2020 and records since 1897 at Red Oak, 8 miles east. NOAA, through RCC-ACIS.