Tennessee Sinkholes

Google map with 43 deep sinkholes

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Tennessee's deepest sinkholes
Waypoint Sinkhole County Locale
BTS001 Bull Sink 122' Blount GSMNP
BTS002 Whiteoak Sink 199' Blount GSMNP
CAS001 Bailey 120' Campbell
CTS001 Sinking Cr 104' Carter
CTS002 Siam Sink 102' Carter
CLS001 Arthur 102' Claiborne
CLS002 Atkins Sink 140' Claiborne
CLS003 Big Sink 165' Claiborne
CLS004 Duncan Hollow 136' Claiborne
CLS005 Goin 100' Claiborne
CLS006 Miracle Pond 114' Claiborne
COS001 Good Hope 118' Cocke
CUS001 Grassy Cove 140' Cumberland
CUS002 Little Cove 130' Cumberland
FRS001 The Big Sink 111' Franklin
FRS002 Wolf Cove 242' Franklin
FRS003 Round Cove 104' Franklin
GUS001 Beersheba 105' Grundy
GUS002 Dykes 156' Grundy
GUS003 Sandstone 103' Grundy
HNS001 Yount Town 109' Hancock
HNS002 Snap 103' Hancock
MIS001 Mitchell Sink 109' Marion
OVS001 Cane Hollow 107' Overton
OVS002 Gore 111' Overton
OVS003 Hoss 133' Overton
OVS004 Hunter 160' Overton
OVS005 Staggs 141' Overton
OVS006 Wilson Mtn 119' Overton
PUS001 Davidson 123' Putnam
PUS002 Icy Cove 206' Putnam
PUS003 Round Cove 150' Putnam
PUS004 Walkers Hollow 100' Putnam
VBS001 Big Sink 123' VanBuren
VBS002 Hills Sink 140' VanBuren
VBS003 Millstone 102' VanBuren
VBS004 Turkey Cot Cove 141' VanBuren
WAS001 Big Sink 142' Warren
WAS002 Brown Mtn 182' Warren
WHS001 Big Sink 261' White
WHS002 Hell Hole 122' White
WHS003 Mill Hole 117' White
WHS004 Pass Cove 118' White
Click on name of sink above for maps/pictures etc.
Waypoints: tnsinks.gpx or tnsinks.mxf
★ Google map/image/topo with deep sinkholes ★
list sorted by depth

There are innumerable sinkholes in Tennessee, and the number is growing. The table above lists only those sinkholes with depths greater than 100'. Initial depths were estimated from USGS digital elevation data (10m DEM, see example or another). The first 34 were discovered by visual examination of online topo maps. Chuck Sutherland later (2013) provided a digital analysis (see below) from 10m DEM using Spatial Analyst in ArcMap that identified 9 more 100'+ sinkholes and provided depth, area, and volume. Big Sink in White County is the deepest (261.4'), but Grassy Cove, a National Natural Landmark, has the biggest area (5 square miles) and largest volume (see below for top 10 in area and volume). Additions and corrections welcome.

There are serveral impact craters in Tennessee, but they are not visually significant.

Visual analysis -- topo reconnaissance

In the 2001 Shofner study, geology students were assigned the task of scanning the state's topo maps (7.5' quadrangles) for sinkholes (hachured contours). A grid was provided for a quadrangle, and the students counted the number of sinkhole contour lines that crossed the grid lines. So rather than just a raw count of sinkholes, the metric accounted somewhat for depth and area. Here are density maps gray scale or color from the study. We were unable to locate the raw data counts from the study.

In 2013 using javascript and on-line topos (CalTopo.com), we clicked on TN sinkholes to record lat,lon. There are over 54,000 sinkholes visible on the 800 USGS TN topo quadrangles. The Talbott quadrangle has over 1,280 sinkholes, and many more uncounted beneath the lake. (By comparison, the Bald Knob quadrangle has the highest number of caves at 345.) Counting sinkholes from the USGS topo maps or the equivalent digital DEM data reveals only the sinkholes that were visible with the photogrammetric techniques used to process the USGS aerial photos. This simple sinkhole count does not account for sinkhole volume (area*depth), so Grassy Cove counts as 1 just like one of the teeny spot sinkholes. Also topo contour interval (10', 20', or 40') can affect the number of sinkholes noted on USGS maps -- 10' contour maps typically showing more sinkholes. Most TN quads are 20' contours. (Ongoing LiDAR aerial surveys should provide more detailed topographic data.)

See various sinkholes per quadrangle maps below:

513 of the state's 803 7.5' quads have at least one sinkhole (64%). 85 of the state's 95 counties have at least one sinkhole (89%). If we refine the data by dividing each quad into a 3x3 grid, then about 30% of the state's 7,227 cells have at least one sinkhole. As an example of the sinkhole clustering, see the Anderson county sinkholes.

Digital analysis 2013

Chuck Sutherland located Tennessee sinkholes in the USGS 10m DEM digital elevation data using Spatial Analyst with ArcMap. The nominal accuracy of USGS topo elevation data is half the contour-interval. Most of Tennessee topos use 20' contour, so the digital analysis summarized here only considers sinkholes with a depth of at least 3m. The ArcMap analysis provides sinkhole location (boundary path), area, perimeter, depth, and volume.

The raw data located 21,365 sinkholes (or depressions) with a depth of at least 3m. It is necessary to review the raw data and remove false sinkholes ("fauxholes"). Outliers include man-made depressions (quarries, gravel pits, clay pits, strip-mine holding ponds, levees, road impoundments) and non-karst depressions such as stream-channel depressions and depressions in the sandy soils of west Tennessee. There were also digital anomalies at some quad boundaries, perhaps, reflecting older DEM data based on 7.5' quadrangles. At least 15.4% of the data were false sinkholes -- scubbing is ongoing.

County Sinkholes DEM 3m+
Robertson 3,602 861
Montgomery 3,025 900
Rutherford 2,988 572
White 2,970 1,070
Jefferson 2,364 773
Not surprisingly, the spatial correlation coefficent is 0.93 for sinkholes per quad for the scrubbed DEM data versus the visual counts per quad (54,0000+). The table at right shows that counties with the most sinkholes have a slightly different order if only sinkholes of depth 3m or more are counted from the DEM data. For all sinkholes, Robertson County had 3,602, but for depths of at least 3m, White county has the most. A table at the bottom of the page show the regional distribution of sinkholes and caves.

Similary, the underlying sinkholes per quad are roughly the same. For all sinkholes visible on topo, the Talbott quadrangle has the highest count at 1,284, but for DEM sinkholes with a depth of at least 3m, the Livingston quad has the highest (391) and Talbott is second (383). (Based on scrubbed 3m+ DEM data). The CDF shows the density of sinkholes (caves) per quad -- 36% of the quads have no visual sinkholes, 42% have no sinkholes of depth 3m+, and 43% have no caves. To see differences in detail of visual analysis sinkholes (black pin) versus the 3m+ DEM sinkholes (red circle) view the Anderson county data, topo sinkholes. There were 625 visual sinkholes on topo map, and the digital analysis reported 239 sinkholes of depth 3m or more (288 unscrubbed). The spatial distribution of visual vs digital sinkholes over Anderson county is roughy the same (hence the high spatial correlation).

The table below lists caves and sinkholes per county and the sinkholes of distinction for each county -- deepest, largest area, largest volume. The last four columns are based on the digital analysis of sinkholes with a depth of at least 3m (scrubbed data).

County Sinkholes Caves sinkholes
3m+
depth
feet
area
km2
volume
m3
Anderson 625 63 239 67.6 0.1671 158,921
Bedford 1,382 109 297 70.2 3.2608 837,298
Benton 12 0 0000
Bledsoe 150 24 55 53.8 0.1061 59,833
Blount 1,080 87 415 199.1 0.6977 1,526,579
Bradley 129 3 30 31.2 0.0612 15,757
Campbell 759 39 287 119.1 0.2779 214,349
Cannon 42 133 15 30.2 0.0251 9,628
Carroll 25 1 4 22.3 0.0582 19,016
Carter 349 69 190 104.3 1.2049 1,284,326
Cheatham 165 33 28 26.9 0.2078 60,897
Chester 3 0 2 23.0 0.0374 10,870
Claiborne 1,641 165 792 164.7 0.4712 1,001,104
Clay 286 48 102 50.5 0.5063 297,250
Cocke 760 63 393 118.1 0.3596 280,828
Coffee 447 67 71 52.5 1.1025 441,673
Crockett 0 0 0000
Cumberland 54 164 24 140.1 13.6108 37,736,946
Davidson 609 87 148 62.0 0.5090 149,152
Decatur 47 19 23 48.9 0.1582 67,901
DeKalb 131 133 54 48.2 0.2021 70,461
Dickson 183 33 62 49.9 0.2900 130,843
Dyer 0 0 0000
Fayette 0 0 0000
Fentress 445 655 156 84.3 0.3529 166,336
Franklin 782 493 180 242.1 4.5087 4,303,666
Gibson 0 0 0000
Giles 193 25 75 52.2 0.2182 88,226
Grainger 1,418 106 588 74.5 0.2336 68,002
Greene 1,618 107 664 86.9 0.7001 553,511
Grundy 78 313 36 155.8 0.4107 163,505
Hamblen 1,491 79 517 72.5 0.5234 193,114
Hamilton 531 84 226 94.8 0.3334 146,848
Hancock 817 81 431 108.9 0.2179 252,806
Hardeman 1 0 0000
Hardin 54 16 24 76.1 0.1994 151,195
Hawkins 1,919 55 780 97.4 0.3878 375,411
Haywood 0 0 0000
Henderson 29 0 1 15.1 0.0073 1,953
Henry 52 0 9 24.6 0.0614 13,007
Hickman 111 85 39 32.8 0.1961 48,473
Houston 72 14 23 26.9 0.0597 17,961
Humphreys 40 4 12 28.2 0.0502 18,308
Jackson 40 75 11 43.0 0.0519 24,332
Jefferson 2,364 103 773 76.8 0.3856 326,747
Johnson 20 25 12 47.9 0.0218 15,469
Knox 1,663 167 697 77.4 2.2135 1,535,832
Lake 0 0 0000
Lauderdale 0 0 0000
Lawrence 27 30 11 21.7 0.1862 47,989
Lewis 9 12 2 42.7 0.0122 7,840
Lincoln 92 18 29 66.6 0.1211 25,922
Loudon 795 22 327 72.5 1.2930 1,065,106
Macon 36 38 12 48.2 0.1237 49,246
Madison 3 0 3 16.4 0.0118 3,466
Marion 110 660 39 108.9 0.0249 16,163
Marshall 2,312 44 366 73.2 0.6609 121,850
Maury 1,347 75 330 42.3 0.2392 93,298
McMinn 427 12 168 49.9 0.2396 105,140
McNairy 1 0 0000
Meigs 246 4 105 47.2 0.1058 65,192
Monroe 696 13 306 94.2 0.6779 360,181
Montgomery 3,025 81 900 84.3 2.6746 1,130,081
Moore 76 14 28 62.3 0.0930 62,127
Morgan 8 2 2 28.9 0.0053 2,046
Obion 0 0 0000
Overton 2,026 564 877 152.2 2.2532 2,971,017
Perry 36 67 19 39.7 0.0744 34,181
Pickett 307 188 134 53.1 0.3581 131,487
Polk 149 6 36 77.4 0.2692 148,011
Putnam 535 575 264 206.0 4.2106 8,530,852
Rhea 203 9 78 47.2 0.1155 81,848
Roane 446 50 197 76.8 0.2637 186,734
Robertson 3,602 162 861 67.9 1.1984 527,084
Rutherford 2,988 130 572 76.8 1.4227 343,784
Scott 6 10 2 12.1 0.0096 1,693
Sequatchie 36 24 14 43.3 0.0821 47,539
Sevier 586 64 236 79.1 0.6025 486,887
Shelby 0 0 0000
Smith 150 105 31 45.9 0.0786 39,636
Stewart 145 14 29 53.5 0.2044 85,549
Sullivan 1,876 167 672 89.2 0.4402 309,614
Sumner 371 42 53 47.6 1.2270 758,651
Tipton 0 0 0000
Trousdale 87 12 22 65.6 0.1368 49,576
Unicoi 3 9 1 23.0 0.0263 10,712
Union 706 58 289 82.3 0.2086 241,526
Van_Buren 653 836 228 141.4 2.2759 1,334,351
Warren 1,596 495 598 182.1 4.8722 3,164,142
Washington 944 39 293 68.6 0.5232 277,137
Wayne 21 37 10 46.9 0.0734 20,042
Weakley 3 0 0000
White 2,970 1,169 1,070 260.5 3.5128 3,987,376
Williamson 217 32 45 38.4 0.0602 17,153
Wilson 1,882 123 331 47.9 0.6967 207,611
county sinkholes of distinction
Metropolitan sinkholes
City Sinkholes per sq
mile
Chattanooga154 1.0
Clarksville1,181 12.3
Jefferson City29 9.1
Knoxville234 3.0
McMinville67 8.4
Nashville608 8.3
Sparta79 13.2

The table at right shows the number of topo sinkholes in a few metropolitan areas. For a coarser state-wide view, see choropleth map and zoom in using topo base map (Caltopo) to see topo sinkholes.

Here are various Google maps of digital analysis for sinkholes with depth of 3m+ on 3x3 grid over topo quad:

The following tables summarize the 3m+ digital data and give the top 10 sinkholes in volume and area.

Sinkhole depth
The following table shows the distribution of depth or greater over the collection of sinkholes.
Depth (ft) Sinkholesraw
3m+ 18,081 21,365
10' 17,522 20,519
20' 7,058 7,977
30' 2,771 3,152
40' 1,195 1,361
50' 569 664
100' 41 53
200' 3 4
The raw data reported 53 deep-hole candidates, but 10 of those were quarries and two were road impoundments. The 43 deepest sinkholes are listed in the table at the top of the page (list sorted by depth). The cumulative distribution show that 50% of the sinkholes have a depth of 16' or less and 95% have a depth of 44' or less. Our visual analysis would suggest there are 36,000+ sinkholes with a depth less than 3m (map). If we had digital data for sinkholes less than 3m, then our CDF's would have a different shape.

Sinkhole area
The following table lists the 10 biggest sinkholes by area (minimum depth 3m).
Sinkhole Area (km2)
Grassy Cove 13.6
Collier 4.9
Sinking Cove 4.5
Burtons 4.2
Old Zion 3.5
Lost Creek 3.5
Byler Bottoms 3.3
Walnut Grove 2.9
Lake Karen 2.7
Fort Campbell 2.7
Some of the sinkholes above do not show an enclosing sinkhole contour on the topo maps, but the digital analysis provides the coordinates for the enclosing path (for example, see Collier). Spatial Analyst seems to underestimate size of Northcutts Cove sinkhole.

The following table shows the cumulative distribution of area over the collection of 3m+ sinkholes (raw and scrubbed data).
Area (km2) Sinkholes raw
0.0006 18,026 21,150
0.001 17,774 20,754
0.01 8,215 9,703
0.1 907 1,152
1 40 53
10 1 1

Sinkhole volume
The following table lists the 10 biggest sinkholes by volume.
Sinkhole Volume
(106m3)
Grassy Cove 37.3
Icy Cove 8.5
Sinking Cove 4.3
Lost Creek 4.0
The Big Sink 4.0
Big Sink 3.2
Big(gest) Sink 3.1
Cane Hollow 3.0
Lake Karen 2.5
Round Cove 2.4

Most of the Tennessee sinkholes are on private property, but you can visit the following:

Spatial density of Tennessee sinkholes and caves

County Sinkholes Caves
Anderson 625 63
Davidson 609 87
Hamilton 531 84
Jefferson 2,364 103
Knox 1,663 167
Marshall 2,312 44
Montgomery 3,025 81
Robertson 3,602 162
Van Buren 653 836
White 2,970 1,169
see ESRI map
The Tennessee Cave Society (TCS) has coordinates for the state's 9,800+ caves (in 2013: 9,839 caves). Using Sutherland's cumulative data for caves-per-county and caves-per-quadrangle, we can compare topo sinkhole and cave density. (The 2001 Shofner study also compared cave and sinkhole density.) The table at right highlights the county cave and sinkhole density (see full table above) and the following maps illustrate the density.

The Shofner paper reports spatial correlation (0.20) between caves and sinkholes. Using our sinkholes/quad count (visual analysis) and TCS caves/quad count, we calculate a spatial correlation of 0.35 for the whole state. The spatial correlation drops to 0.30 if we exclude quads with no caves and no sinkholes. The correlation of caves to sinkholes of 3m+ depth (digital analysis) is 0.26. About 36% of the state 7.5' quads and 10 of the 95 counties have no caves and no sinkholes.

Notable public caves Lost Sea, Ruby Falls, Dunbar Cave, Bell Witch Cave, Big Bone Cave, Cumblerland Caverns, Tuckaleechee Caverns, Raccoon Mountain Caverns, and Forbidden Caverns

Caves and surface geology:

Additional information

 

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   © Tom Dunigan
Revised Tue, 26 Aug 2014 15:45:33 -0600