In aerial archaeology, this word follows crop when describing certain man-made features, positive examples of which promote vegetation while negative examples, like buried walls, dissuade plant growth. For 10 points each:
[10h] Give this word, that follows “soil” and “frost” when describing slight differences observed from the air when the mediums interact with ruins. Shadow[this word] are caused by elevation differences observed in extant ruins.
ANSWER: mark [accept cropmarks or crop marks; accept frost marks; accept soil marks; accept shadow marks; prompt on shadow reliefs]
[10e] One way to discover crop marks is to use this technology to observe temperature changes caused by water loss. This technology, which detects infrared radiation, is a typical part of modern KAP kits that take pictures from kites.
ANSWER: thermal imaging [accept thermal video or infrared thermography or IRT; accept Near Infrared Spectroscopy or NIR]
[10m] Cropmarks can “deepen” into parch marks during these periods, which can also narrow tree rings. Low levels of solar radiation and the southwards shift of the ITCZ may have caused one of these events linked to the Mayan collapse.
ANSWER: droughts [accept heatwaves or other answers that indicate periods of excess heat; prompt on famine by asking “what caused the famine?”]