interstadial; interstade
Geology term for a relatively warm period within a glacial stage, shorter and less pronounced than an interglacial.
Several interstadials are recognized within the last glacial period.
間氷期 (interglacial) is a longer, warmer period between glacial stages, while 亜間氷期 is a shorter warm phase within a glacial stage.
Compound of 亜 (sub-), 間 (between), 氷 (ice), and 期 (period), literally 'sub-interglacial period'. The exact historical derivation is uncertain; the spelling is conventionally associated with the geological meaning.