Bamum script, Lake Nyos and Diy-Gid-Biy

Bamum script changes affected glyph meaning as well as the size of its inventory. A 2009 Unicode proposal gives raˀ as an example: it carried the reading “reconciled” in Phases A–E, then the syllabic reading ŋa (“here”) in Phase F. The example shows that the glyph’s form could carry forward even as its meaning changed. Njoya’s 1910 revision left a 70-character script; the modern proposal describes 80 base characters, with the last ten also used as digits.[1][2][3]

The 1986 disaster and the later degassing record describe different stages of Lake Nyos’s history. The 1987 Science article’s abstract, available through Zenodo, says the release on 21 August killed at least 1,700 people; it identifies carbon dioxide accumulated in deep lake water as the principal gas and reports no significant direct volcanic activity. A complete 2005 PNAS article describes controlled degassing at Nyos from 2001, with a pipe drawing water from 203 m, and records total gas pressure of 15.6 bar in 2001. Ohba and colleagues’ 2022 paper gives the dissolved CO₂ inventory as 14.8 Gmol in 2001 and 3.9 Gmol by 2015, citing earlier measurements.[6][7][8]

The 2025 ICOMOS evaluation describes Diy-Gid-Biy through its archaeological remains and Mafa ritual use. It describes sixteen dry-stone ruins across seven villages in Cameroon’s Far North. Mafa communities use the ruins for rituals associated with ancestral spirits; ICOMOS records sacrifices as the wet season opens and again as it closes. UNESCO’s site account adds that each village has a ritual guardian and that customary taboos restrict access outside ceremonies. ICOMOS notes that no written or oral source has yet identified the builders. Its chronology dates some walls to the 12th century, while radiocarbon results place construction in the 15th century or later for most sites.[9][10]