iridium-rich level
166
through weak bonds and as hydrogen bonds. The ionic radius of these
hydrated ions determines the physical properties of ions in water, like their
velocity to pass through membranes.
iridium-rich level thin lamina of sediment (varying from 2 to 15 mm) highly
enriched in iridium, which marks the extinction level at the Cretaceous-Tertiary
boundary. The iridium has an extraterrestrial origin; an important aspect of
this level is that it respresents a globally synchronous event. --7extinction and
--7biostratigraphy.
irradiance the amount of radiant energy per unit area falling on a surface.
Irradiance is typically measured in units of watts per square centimeter. In
the sea the surface is usually taken horizontally, and we can find a downward
and upward irradiance.
irrotational flow --7potential flow.
Isabella Expedition (1818) under John Ross was ordered by the English admiralty to sail west of Greenland to the North and try to find the so-called North
West Passage along the American coast to the Pacific, accompanied by the
Alexander under E. Parry. In addition to magnetical, meteorological and
gravity measurements, Ross' instructions included some marine research
viz. the study of current directions, depth of the sea, nature of the bottom
and sampling of seawater. Ross designed new instruments during the expedition such as a deep-sea "clamm", a heavy iron grab under the sounding
lead, intended to recover a large quantity of bottom sediment. Ross discovered such sediment samples to preserve the temperature of the seabed for
some time and measured a temperature of 29.5 OF (= -0.7 0c) in mud from
420 fathoms depth. Ross also collected bottom-dwelling organisms from
depths greater than were thought habitable at that time. Probably due to the
failure of the expedition to find the North West passage, these important scientific discoveries were overlooked and the myths of an azoic zone below
300 fathoms and of a uniform temperature of 4 °C of the deep sea long
remained popular.
isentropic analysis --7isentropic surface.
isentropic surface a surface in a fluid where the entropy is constant. It is also called
a neutral surface. In the ocean transport along isentropic surfaces is generally thought to be the main component of lateral turbulent transport of heat
and salt. Therefore isentropic analysis, i.e., analysis of the distribution of properties in such a surface, is often used to study the spreading and mixing of
water masses. In first approximation, surfaces of constant potential density relative to an appropriate pressure are used as isentropic surfaces.
166
through weak bonds and as hydrogen bonds. The ionic radius of these
hydrated ions determines the physical properties of ions in water, like their
velocity to pass through membranes.
iridium-rich level thin lamina of sediment (varying from 2 to 15 mm) highly
enriched in iridium, which marks the extinction level at the Cretaceous-Tertiary
boundary. The iridium has an extraterrestrial origin; an important aspect of
this level is that it respresents a globally synchronous event. --7extinction and
--7biostratigraphy.
irradiance the amount of radiant energy per unit area falling on a surface.
Irradiance is typically measured in units of watts per square centimeter. In
the sea the surface is usually taken horizontally, and we can find a downward
and upward irradiance.
irrotational flow --7potential flow.
Isabella Expedition (1818) under John Ross was ordered by the English admiralty to sail west of Greenland to the North and try to find the so-called North
West Passage along the American coast to the Pacific, accompanied by the
Alexander under E. Parry. In addition to magnetical, meteorological and
gravity measurements, Ross' instructions included some marine research
viz. the study of current directions, depth of the sea, nature of the bottom
and sampling of seawater. Ross designed new instruments during the expedition such as a deep-sea "clamm", a heavy iron grab under the sounding
lead, intended to recover a large quantity of bottom sediment. Ross discovered such sediment samples to preserve the temperature of the seabed for
some time and measured a temperature of 29.5 OF (= -0.7 0c) in mud from
420 fathoms depth. Ross also collected bottom-dwelling organisms from
depths greater than were thought habitable at that time. Probably due to the
failure of the expedition to find the North West passage, these important scientific discoveries were overlooked and the myths of an azoic zone below
300 fathoms and of a uniform temperature of 4 °C of the deep sea long
remained popular.
isentropic analysis --7isentropic surface.
isentropic surface a surface in a fluid where the entropy is constant. It is also called
a neutral surface. In the ocean transport along isentropic surfaces is generally thought to be the main component of lateral turbulent transport of heat
and salt. Therefore isentropic analysis, i.e., analysis of the distribution of properties in such a surface, is often used to study the spreading and mixing of
water masses. In first approximation, surfaces of constant potential density relative to an appropriate pressure are used as isentropic surfaces.