Alaska

Washington

Wyoming

Hawaii

Oregon

None

A world map showing volcanoes active between 1800 and 2020. Volcanoes are scattered globally, with notable concentrations in the western US, Mexico, Central America, the Andes, the Mediterranean, East Africa, Southeast Asia, and the Pacific Ring of Fire.

Time series map animation showing locations of significant volcanic eruptions from 1800 to 2019. Use timeline controls at bottom of the map to display data by time period.

Volcanoes

World

NOAA

Florida

Rhode Island

Maine

Nova Scotia

Virginia

Delaware

Prince Edward Island

North Carolina

New Brunswick

British Columbia

Newfoundland and Labrador

New Jersey

Massachusetts

Georgia

New York

Maryland

California

A map illustrates the distribution of calcium carbonate in modern surface sediments globally, with highest concentration found in the Caribbean, Mediterranean, and South Pacific and lowest concentration dominating the North Pacific, and Southern Ocean.

Percentage of ocean surface comprised of calcium carbonate.

Distribution of Calcium Carbonate in Modern Surface Sediments

The distribution is represented as a percentage by weight. Areas with the least calcium carbonate, ranging from 0 percent to 20 percent, are marked in very light blue and are prevalent in large parts of the Pacific Ocean, particularly around Samoa, the South Pacific, and parts of the Indian Ocean. Light blue regions, representing 20 percent to 40 percent calcium carbonate, cover parts of the North Atlantic Ocean, including areas around Cuba, the western coast of Africa near Senegal and Mauritania, and the southern Indian Ocean near Madagascar. Medium blue areas, indicating 40 percent to 60 percent calcium carbonate, include regions in the North Atlantic Ocean, off the coast of the United Kingdom and France, the Mediterranean Sea, parts of the Arabian Sea, and the South Pacific Ocean. Blue-green regions, with 60 to 80 percent calcium carbonate, are seen in the central Atlantic Ocean, areas around the Caribbean including Cuba and Guatemala, the western coast of Africa near Gabon and Angola, and the Indian Ocean. The highest concentration of calcium carbonate, 80 percent to 100 percent, marked in dark green, is found in regions of the North Atlantic Ocean, around the Bahamas and north of Cuba, parts of the South Atlantic Ocean near the eastern coast of South America, the central Pacific Ocean, and the northern Indian Ocean near Sri Lanka.

Oceans

WDC-MARE Reports

Percent by weight

Arizona

Utah

District of Columbia

Idaho

New Hampshire

Vermont

Montana

North Dakota

Kentucky

Mississippi

West Virginia

Nebraska

Texas

Missouri

Louisiana

Alabama

New Mexico

Kansas

Wisconsin

South Carolina

Michigan

Connecticut

Pennsylvania

Colorado

Nevada

Oklahoma

Tennessee

Arkansas

South Dakota

Ohio

Indiana

Minnesota

Iowa

Illinois

A map shows the p H levels of acid rain in the U.S. States like Ohio and Pennsylvania have the lowest p H levels (4.50 to 4.59 p H, black). States like Arizona and Nevada show the highest p H levels (greater than or equals 5.30 p H, light yellow).

Average acidity of precipitation in the United States. Lower pH values represent greater acidity.

Acid Rain (U.S.)

United States

Geosystems: Intro to Physical Geography

Acid Rain

A map shows the population of unauthorized immigrants in the U.S. States like California and Texas have the highest numbers (dark blue). States like Montana, North Dakota, and Vermont show the lowest numbers (lighter blue).

Estimated unauthorized immigrant population in the United States, by state

Display by:	Volcanoes	Distribution of Calcium Carbonate in Modern Surface Sediments					Acid Rain									Unauthorized Immigrant Population (U.S.)
	Volcanoes	0 - 20	20 - 40	40 - 60	60 - 80	80 - 100	4.50–4.59 pH	4.60–4.69 pH	4.70–4.79 pH	4.80–4.89 pH	4.90–4.99 pH	5.00–5.09 pH	5.10–5.19 pH	5.20–5.29 pH	≥5.30 pH	Class	Rank	Millions people
Nova Scotia		3.14%
Prince Edward Island		19.7%
New Brunswick		0.602%
British Columbia		0.699%
Newfoundland and Labrador		1.91%
Alabama											84.6%	13.4%					31	62,000
Alaska	1	0.671%															44	10,000
Arizona														1.23%	98.8%		9	273,000
Arkansas												17.5%	40.8%	7.44%	10.2%		32	58,000
California		0.408%	0.184%												99.7%		1	2,739,000
Colorado													1.85%	3.55%	88.3%		15	162,000
Connecticut									49.9%	50.0%							18	113,000
Delaware		2.57%							17.4%	81.8%							41	24,000
District of Columbia									100%								42	21,000
Florida				0.637%		0.865%				1.32%	13.8%	25.9%					4	772,000
Georgia				0.250%						7.01%	3.21%	2.51%	3.47%				7	339,000
Hawaii	3	2.48%	13.2%		3.56%	1.64%											33	51,000
Idaho														4.63%	95.4%		38	29,000
Illinois											39.9%	27.0%	15.0%	3.08%	9.73%		6	425,000
Indiana									12.8%	4.37%	8.75%	5.18%					20	102,000
Iowa														1.50%	98.5%		37	37,000
Kansas															100%		29	69,000
Kentucky									1.72%	54.3%	1.61%	9.53%					35	46,000
Louisiana											41.6%	42.5%	8.80%	4.48%	2.23%		27	70,000
Maine		0.825%									17.3%	69.8%	10.8%				48	5,000
Maryland		2.92%							12.5%	29.8%	10.3%						12	225,000
Massachusetts		5.64%			0.220%					98.2%							13	209,000
Michigan										24.0%	10.0%	4.73%	13.3%				21	91,000
Minnesota													2.86%	4.42%	92.3%		26	81,000
Mississippi											14.3%	79.0%	5.27%				39	25,000
Missouri												26.1%	26.9%	12.0%	34.2%		34	50,000
Montana														9.26%	90.7%		51	3,000
Nebraska															100%		36	42,000
Nevada															100%		14	168,000
New Hampshire										72.0%	27.9%						43	11,000
New Jersey		1.77%						5.98%	36.6%	32.6%	23.7%						5	440,000
New Mexico														4.15%	91.3%		30	63,000
New York		3.00%						4.25%	52.6%	35.3%							3	835,000
North Carolina		1.08%							1.35%	37.2%	1.72%	9.88%					8	296,000
North Dakota															100%		47	5,000
Ohio							5.07%	9.56%	59.7%	23.0%							23	89,000
Oklahoma													2.73%	5.70%	91.6%		22	90,000
Oregon	2	0.120%												2.68%	97.3%		19	108,000
Pennsylvania							3.58%	34.8%	29.1%	10.8%							16	153,000
Rhode Island		4.44%							2.00%	3.88%							40	24,000
South Carolina										33.6%	64.2%	2.08%					25	88,000
South Dakota															100%		46	7,000
Tennessee									5.63%	19.5%	14.5%	3.55%					17	128,000
Texas											8.53%	1.49%	4.74%	5.19%	56.4%		2	1,739,000
Utah														1.69%	98.3%		24	89,000
Vermont										95.7%	4.07%						50	3,000
Virginia		0.818%							3.50%	1.66%	15.4%						10	251,000
Washington	2	1.05%												23.4%	70.9%		11	246,000
West Virginia								7.63%	45.0%	12.8%	8.92%						49	4,000
Wisconsin												4.01%	46.8%	27.3%	21.3%		28	70,000
Wyoming	1														100%		45	7,000

MapMaster 3

Volcanoes