Ice concentration is measured in tenths....

🔍 Key Concepts

• World Meteorological Organization (WMO) sea ice concentration scale and its terms like open drift, close pack, very close pack, and compact ice • How ice concentration in tenths relates to how much open water is still visible • The difference between moderate, close, and very close pack ice in operational ice navigation

💭 Think About

• Think about what the word "close" suggests about how much open water is left between the ice floes. • Compare the options and ask yourself: in which range would ship maneuvering space start to become seriously restricted, but not yet at the absolute maximum concentration? • Consider which ranges are more likely to describe scattered ice versus nearly continuous ice cover.

✅ Before You Answer

• Verify which range is used for very close pack / compact ice (almost no open water) and then step down one level to find "close pack." • Check that the range you select leaves some room for navigation but would still be considered hazardous and restrictive for most vessels. • Eliminate any ranges that clearly describe ice that is either too sparse (lots of open water) or essentially solid with almost no gaps.

Ice concentration is measured in tenths. What concentration range of ice corresponds to "Close Pack"?

9 - 10 tenths

7 - 8 tenths

4 - 6 tenths

1 - 3 tenths

🔍 Key Concepts

💭 Think About

✅ Before You Answer