LOCATION KILAUEA HIEstablished Series
TAXONOMIC CLASS: Ashy, ferrihydritic, nonacid, isothermic Udic Ustorthents
TYPICAL PEDON: Kilauea very gravelly ashy sandy loam, 4 percent slope on a volcanic hill under sparse ohia trees and shrubs at an elevation of 1,103 meters (3,620 feet). 75 percent of the soil surface is covered by a reddish brown (5YR 4/3) brittle crust 1 centimeter (0.5 inches) thick. (Colors are lithochromic. Colors are for moist soil unless otherwise noted. When described on 10/1/96 the soil was moist throughout. All textures are "apparent field textures". pH was determined by adjusting field organic dye values via regression to approximate pH in 1:1 water.)
Cm--0 to 1 centimeter (0 to 0.5 inches); cemented crust; when crushed, dark reddish gray (5YR 4/2) very gravelly ashy sandy loam, dark reddish gray (5YR 4/2) dry; 10 percent thin white coats on underside of crust; 65 percent subrounded pyroclastic gravel; ultra acid (pH 3.1); abrupt wavy boundary. (0 to 5 centimeters (0 to 2 inches) thick)
C1--1 to 8 centimeters (0.5 to 3 inches); black (10YR 2/1) very gravelly ashy sand, dark gray (10YR 4/1) dry; stratified; soft, loose, nonsticky and nonplastic; few very fine and fine roots; many very fine, fine, and medium interstitial pores; 60 percent subrounded pyroclastic gravel; strongly acid (pH 5.4); abrupt wavy boundary.
C2--8 to 13 centimeters (3 to 5 inches); very dark grayish brown (10YR 3/2) ashy sandy loam, grayish brown (10YR 5/2) dry; massive; hard, firm, nonsticky and nonplastic; few very fine and fine roots; many very fine and fine interstitial pores; 5 percent subrounded pyroclastic gravel; neutral (pH 6.9); abrupt wavy boundary.
C3--13 to 18 centimeters (5 to 7 inches); black (10YR 2/1) very gravelly ashy sand, dark gray (10YR 4/1) dry; stratified; loose when moist or dry, nonsticky and nonplastic; few very fine and fine roots; many very fine, fine, and medium interstitial pores; 40 percent subrounded pyroclastic gravel; neutral (pH 6.9); abrupt wavy boundary.
C4--18 to 25 centimeters (7 to 10 inches); dark brown (7.5YR 3/2) very gravelly ashy loamy sand, reddish gray (5YR 5/2) dry; massive; slightly hard, friable, nonsticky and nonplastic; few very fine and fine roots, matted at bottom of horizon; many very fine and fine interstitial pores; 40 percent subrounded pyroclastic gravel; neutral (pH 6.9); abrupt wavy boundary.
C5--25 to 51 centimeters (10 to 20 inches); stratified layers of very gravelly ashy coarse sand and very gravelly loamy sand; 50 percent black (7.5YR 2/1) moist and grayish brown (10YR 5/2) dry, and 50 percent very dark brown (10YR 2/2) moist and dark yellowish brown (10YR 4/4) dry; loose when moist or dry, nonsticky and nonplastic; few very fine and fine roots; many very fine, fine, and medium interstitial pores; 60 percent subrounded pyroclastic gravel; neutral (pH 7.2); abrupt wavy boundary.
C6--51 to 58 centimeters (20 to 23 inches); black (10YR 2/1) gravelly ashy sand, gray (10YR 5/1) dry; massive; loose when moist or dry, nonsticky and nonplastic; few very fine and fine roots; many very fine and fine interstitial pores; 20 percent subrounded pyroclastic gravel; neutral (pH 7.2); abrupt wavy boundary.
C7--58 to 96 centimeters (23 to 38 inches); very dark grayish brown (2.5Y 3/2) ashy very fine sand and sand, dark grayish brown (2.5Y 4/2) dry; stratified; soft and slightly hard, loose, nonsticky and nonplastic; few very fine and fine roots; many very fine and fine interstitial pores; slightly alkaline (pH 7.5); abrupt wavy boundary. (2.5 to 63 centimeters (1 to 25 inches) thick)
C8--96 to 102 centimeters (38 to 40 inches); black (N 2/0) gravelly ashy sand, dark brown (10YR 3/3) dry; massive; loose when moist or dry, nonsticky and nonplastic; few very fine and fine roots; many very fine, fine, and medium interstitial pores; 20 percent subrounded pyroclastic gravel; slightly alkaline (pH 7.5); abrupt wavy boundary. (5 to 20 centimeters (2 to 8 inches) thick)
C9--102 to 142 centimeters (40 to 56 inches); very dark grayish brown (2.5Y 3/2) and olive brown (2.5Y 4/3) ashy very fine sand; massive; soft, loose, nonsticky and nonplastic; few very fine and fine roots; many very fine and fine interstitial pores; slightly alkaline (pH 7.5); abrupt wavy boundary. (38 to 102 centimeters (15 to 40 inches) thick)
C10--142 to 190 centimeters (56 to 75 inches); black (N 2/0) coarse sand, gray (10YR 5/1) dry; platy and massive; soft, loose, nonsticky and nonplastic; few very fine and fine roots; many very fine, fine, and medium interstitial pores; few prominent patchy sulfur coatings on lower surface of peds or gravel; 10 percent subrounded pyroclastic gravel; slightly alkaline (pH 7.5).
TYPE LOCATION: Hawaii Volcanoes National Park; from Park headquarters, travel 4.1 miles south on Crater Rim Drive (past Volcano Observatory) to road pullout; turn west onto gravel track and drive south and parallel to road for 0.1 mile; turn west following road marked by cairns and travel 0.2 mile; walk 4 meters (12 feet) south to crack; Kilauea Crater Quadrangle; lat. 19 degrees 24 minutes 11.99 seconds N. and long. 155 degrees 17 minutes 58.45 seconds W. (Old Hawaiian Datum measured by GPS/PLGR.)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 17 or 18 degrees C. (63 or 64 degrees F.)
Surface crust: Covers 65 to 80 percent of the soil surface.
Depth to bedrock: 100 to 190 centimeters (40 to 75 inches) or more.
Soil reaction: Ultra acid to strongly acid in the surface three inches and slightly acid to slightly alkaline in the underlying layers.
C horizon
Texture: Ashy sandy loam to ashy coarse sand.
Structure: Platy, single, or massive.
Rock fragments: 15 to 40 percent in upper 25 centimeters (10 inches); 20 to 35 percent in control section.
Olivine crystals: Occur in most pedons.
Sulfur coatings: Occur in few pedons.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Kilauea soils are on lava flows and spatter cones adjacent to Kilauea Crater at elevations of 1,067 to 1,128 meters (3,500 to 3,700 feet). Slopes range from 2 to 10 percent. The mean annual rainfall is 1,016 to 1,524 millimeters (40 to 60 inches), with about 90 percent of the rainfall occurring between October and May. The mean annual pan evaporation is 1,524 to 1,905 millimeters (60 to 75 inches). The mean annual air temperature is about 16 degrees C. (60 degrees F.)
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Halema`uma`u, Heake, and Lithic Haplustands soils and Cinder land. Halema`uma`u soils are moderately deep over pahoehoe bedrock and have accretionary lapili and reticulite. Heake and Lithic Haplustands soils are lithic, less than 50 centimeters (20 inches) over pahoehoe. Cinder land consist primarily of cinders.
DRAINAGE AND PERMEABILITY: Excessively drained. In areas with surface crust, runoff is very high and permeability is very slow. In areas without surface crust, runoff is very low and permeability is rapid.
USE AND VEGETATION: These soils are used for National Park Service land. Vegetation is sparse and composed of `a`ali`i (Dodonaea viscosa), broomsedge (Andropogon virginicus), bush beardgrass (Schizachyrium condensatum), kukae-nene (Coprosma ernodeoides), `ohelo (Vaccinium reticulatum), `ohi`a lehua (Metrosideros polymorpha), and pukiawe (Styphelia tameiameiae).
DISTRIBUTION AND EXTENT: These soils are within Hawaii Volcanoes National Park, west of Kilauea Crater; MLRA 161. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Island of Hawaii, Hawaii County, Hawaii, 1949.
REMARKS: Soil Temperature - mean summer and mean winter soil temperatures differ by less than 6 degrees C. (iso temperature regime).
Soil moisture - dry in some or all parts for 90 days or more in most years (Ustic moisture regime).
Soil reaction - low pH in the surface layer is attributed to sulfur fumes from volcanic vents and acid rain.
Edit Log: 12/03 KH. Added "ashy" modifier to textures.
3/01 KH. Drainage changed from somewhat excessive.
9/99 KH. Type location changed. Classification changed due to changes in Taxonomy, and based on lab data.
ADDITIONAL DATA: Kilauea reference sample (soil crust) NSSL S96-HI-001-009 and S96-HI-001-010, and grab sample S97HI-001-003.
Penetrometer measurements
Cm horizon = >4 tons/square foot
C2 horizon = 2 tons/square foot
C3 horizon = 4 tons/square foot
Penetrometer measurements were made by inserting penetrometer horizontally into "in situ" soil.