thermal a rising column of warm air.
thermosphere the stratum of Earth's atmosphere from 50 to 300 miles up that contains ionized bands, collectively known as the ionosphere.
troposphere the stratum of Earth's atmosphere from 0 to 10 miles up, where most weather systems occur.
ultraviolet radiation a form of radiation from the sun, most of which is absorbed or blocked by the Earth's ozone layer.
X-rays a form of the Sun's radiation, which is filtered or absorbed by the Earth's thermosphere.
beaches and shores
barchan a crescent-shaped sand dune.
barrier beach a large, low-lying sand bar surrounded by the sea.
barrier reef a long, narrow ridge or rock or coral running parallel to the shore and separated from the beach by deep water.
bay a broad-mouthed inlet of the sea that is larger than a cove but smaller than a gulf.
berm a large terracelike ledge or shelf of sand deposited on a beach over time.
bluff a steep embarkment or headland cut or eroded by the sea.
bore a dangerous, often high wave caused by an incoming tide surging upstream in a narrowing estuary; can also be caused by the collision of tidal currents. Also known as an eagre.
cape any body of land projecting into the ocean.
cay a small island composed of sand or coral.
channel a waterway between two land masses. Also, a deep course navigable by large boats or ships.
cove a small bay, especially one that is sheltered by steep banks or promontories.
crest the top of a wave.
cusps curving mounds of sand several feet long set at regular intervals, caused by the sea breaking at right angles to the beach.
detritus eroded particles of plants, sea creatures, and rocks littering the beach.
eagre high, dangerous wave caused by an incoming tide surging upstream in a narrowing estuary.
ebb tide a receding tide.
eel grass a type of seaweed.
embayment a small bay or cove.
estuary an area where a river flows into the ocean.
feldspar common mineral particle found in beach sand.
fetch the distance wind travels from one point on the sea to another and its relation to the size of waves created; the longer the fetch or distance, the bigger the waves.
fjord a long inland arm of ocean surrounded on either side by cliffs or steep banks.
flotsam and jetsam debris, goods, or cargo cast or washed from an imperiled or wrecked ship.
foredune the dune or dunes immediately facing the sea; the closest dune to the shore.
foreshore the shore uncovered by a receding tide.
garnet a common mineral component found in beach sand.
graybeards any frothy or gray-crested waves.
groin a short jetty of stone or other material built at right angles to the shore to catch sand and help combat beach erosion.
gulf a broad expanse of ocean that extends inland and is considerably larger than a bay.
headland a high point of land extending out into the water; a promontory.
inlet an estuary or narrow bay.
isthmus a narrow strip of land extending into the water and joining two land masses, such as a mainland beach and an island.
jetty a structure of rocks or other material extending out into the water to protect a harbor.
key a low coral island, islet, or reef.
lagoon a small, shallow body of water sheltered from the sea by a reef or sandbar.
lee shore a shore protected from the wind, a haven for vessels because of its calmer sea.
littoral pertaining to the shore area.
longshore current a narrow current caused by diagonally breaking waves, known to move large quantities of sand and to build up new or existing beaches.
mermaid's purse a brown, pillowlike object with a tendril extending from each corner; the leathery egg case of a skate, commonly found on many beaches.
neap tide the minimal or low-moving tide occurring after the first and third quarters of the Moon, when the Sun's tidal force acts at right angles to that of the Moon.
parabolic dune a U-shaped beach dune with the open end toward the sea.
peninsula a large land mass bordered on three sides by the sea and connected to a mainland by an isthmus.
plunger a wave with a convex back and a crest that falls suddenly and violently, the most common type of beach wave.
pocket beach a small sand beach contained within an embayment between two cliffed headlands.
point a land mass that projects into the sea and ends in a narrow tip.
promontory headland.
quartz the most common component of beach sand.
red tide a bloom of phytoplankton that colors the water red and releases powerful toxins that kill large populations of fish and taint clams and mussels, making them hazardous for humans to eat.
rill a small water channel formed when a beach is saturated.
riptide a cross or conflicting current making for dangerous swimming conditions.
rockweed a rock-clinging seaweed.
sandbar a ridge of sand formed along beaches.
seaboard a coastline.
seashell The following are common types of sea- shells: abalone, angel wings, baby bonnet, cask, clam, cockle, conch, cone, cowrie, horn, horse conch, limpet, mottled Venus, mussel, nautilus, oyster, periwinkle, razor, scallop, sea pen, slipper, triton, wentletrap.
shingle beach a beach consisting of small, flat stones and a steep slope descending into deep water with little or no surf, commonly seen in England.
shoal a shallow area formed by a reef or sandbar, hazardous to boating.
skerry a small reef or rocky island.
spiller a wave with a concave back and a crest that breaks gradually and continuously, most often seen offshore.
spindrift sea spray.
spit a narrow point of land extending into the water.
spring tide the highest and lowest tide occurring at new and full Moon and reinforced by the alignment with the Sun.
stack a small island of rock isolated from land and set apart from the head of a promontory.
strait any narrow channel connecting two larger bodies of water.
strand a beach or shoreline.
swash a wave's shallow sweep up a beach; a receding swash is also known as backwash.
swashmarks long, interlacing ripples and strands of marine debris left by a receding swash.
tide the rise and fall of the sea due to the gravitational pull of the Sun and Moon.
tideland any land that is submerged at high tide.
tidemark any human-made or organic mark that indicates the sea's highest point during high tide.
tide pool a small body of seawater—varying from the size of a bathtub to that of a swimming pool—left behind by a withdrawing tide, and frequently teeming with marine life.
tidewater water that floods tideland at high tide.