United States vs. Mexico

tsunamis; volcanoes; earthquake activity around Pacific Basin; hurricanes along the Atlantic and Gulf of Mexico coasts; tornadoes in the Midwest and Southeast; mud slides in California; forest fires in the west; flooding; permafrost in northern Alaska, a major impediment to development

volcanism: volcanic activity in the Hawaiian Islands, Western Alaska, the Pacific Northwest, and in the Northern Mariana Islands; both Mauna Loa (4,170 m) in Hawaii and Mount Rainier (4,392 m) in Washington have been deemed Decade Volcanoes by the International Association of Volcanology and Chemistry of the Earth's Interior, worthy of study due to their explosive history and close proximity to human populations; Pavlof (2,519 m) is the most active volcano in Alaska's Aleutian Arc and poses a significant threat to air travel since the area constitutes a major flight path between North America and East Asia; St. Helens (2,549 m), famous for the devastating 1980 eruption, remains active today; numerous other historically active volcanoes exist, mostly concentrated in the Aleutian arc and Hawaii; they include: in Alaska: Aniakchak, Augustine, Chiginagak, Fourpeaked, Iliamna, Katmai, Kupreanof, Martin, Novarupta, Redoubt, Spurr, Wrangell, Trident, Ugashik-Peulik, Ukinrek Maars, Veniaminof; in Hawaii: Haleakala, Kilauea, Loihi; in the Northern Mariana Islands: Anatahan; and in the Pacific Northwest: Mount Baker, Mount Hood; see note 2 under "Geography - note"

tsunamis along the Pacific coast, volcanoes and destructive earthquakes in the center and south, and hurricanes on the Pacific, Gulf of Mexico, and Caribbean coasts

volcanism: volcanic activity in the central-southern part of the country; the volcanoes in Baja California are mostly dormant; Colima (3,850 m), which erupted in 2010, is Mexico's most active volcano and is responsible for causing periodic evacuations of nearby villagers; it has been deemed a Decade Volcano by the International Association of Volcanology and Chemistry of the Earth's Interior, worthy of study due to its explosive history and close proximity to human populations; Popocatepetl (5,426 m) poses a threat to Mexico City; other historically active volcanoes include Barcena, Ceboruco, El Chichon, Michoacan-Guanajuato, Pico de Orizaba, San Martin, Socorro, and Tacana; see note 2 under "Geography - note"

note 1: world's third-largest country by size (after Russia and Canada) and by population (after China and India); Denali (Mt. McKinley) is the highest point (6,190 m) in North America and Death Valley the lowest point (-86 m) on the continent

note 2: the western coast of the United States and southern coast of Alaska lie along the Ring of Fire, a belt of active volcanoes and earthquake epicenters bordering the Pacific Ocean; up to 90% of the world's earthquakes and some 75% of the world's volcanoes occur within the Ring of Fire

note 3: the Aleutian Islands are a chain of volcanic islands that divide the Bering Sea (north) from the main Pacific Ocean (south); they extend about 1,800 km westward from the Alaskan Peninsula; the archipelago consists of 14 larger islands, 55 smaller islands, and hundreds of islets; there are 41 active volcanoes on the islands, which together form a large northern section of the Ring of Fire

note 4: Mammoth Cave, in west-central Kentucky, is the world's longest known cave system with more than 650 km (405 miles) of surveyed passageways, which is nearly twice as long as the second-longest cave system, the Sac Actun underwater cave in Mexico - the world's longest underwater cave system (see "Geography - note" under Mexico);

note 5: Kazumura Cave on the island of Hawaii is the world's longest and deepest lava tube cave; it has been surveyed at 66 km (41 mi) long and 1,102 m (3,614 ft) deep

note 6: Bracken Cave outside of San Antonio, Texas is the world's largest bat cave; it is the summer home to the largest colony of bats in the world; an estimated 20 million Mexican free-tailed bats roost in the cave from March to October making it the world's largest known concentration of mammals

note 7: the US is reliant on foreign imports for 100% of its needs for the following strategic resources - Arsenic, Cesium, Fluorspar, Gallium, Graphite, Indium, Manganese, Niobium, Rare Earths, Rubidium, Scandium, Tantalum, Yttrium; see Appendix H: Strategic Materials for further details

note 8: three food crops are generally acknowledged to be native to areas of what is now the United States: cranberries, pecans, and sunflowers

note 1: strategic location on southern border of the US; Mexico is one of the countries along the Ring of Fire, a belt of active volcanoes and earthquake epicenters bordering the Pacific Ocean; up to 90% of the world's earthquakes and some 75% of the world's volcanoes occur within the Ring of Fire

note 2: some of the world's most important food crops were first domesticated in Mexico; the "Three Sisters" companion plants - winter squash, maize (corn), and climbing beans - served as the main agricultural crops for various North American Indian groups; all three apparently originated in Mexico but then were widely disseminated through much of North America; avocado, amaranth, and chili peppers also emanate from Mexico, as does vanilla, the world's most popular aroma and flavor spice; although cherry tomatoes originated in Ecuador, their domestication in Mexico transformed them into the larger modern tomato

note 3: the Sac Actun cave system at 348 km (216 mi) is the longest underwater cave in the world and the second longest cave worldwide, after Mammoth Cave in the United States (see "Geography - note" under United States)

note 4: the prominent Yucatan Peninsula that divides the Gulf of Mexico from the Caribbean Sea is shared by Mexico, Guatemala, and Belize; just on the northern coast of Yucatan, near the town of Chicxulub (pronounce cheek-sha-loob), lie the remnants of a massive crater (some 150 km in diameter and extending well out into the Gulf of Mexico); formed by an asteroid or comet when it struck the earth 66 million years ago, the impact is now widely accepted as initiating a worldwide climate disruption that caused a mass extinction of 75% of all the earth's plant and animal species - including the non-avian dinosaurs