Porcupine Abyssal Plain

advective equation Aunggyantha Babadag-Dagh circumferential seam joint cold-hardened Echinops sylvicola fast fragment flag-state geographical regions impredictably non-degenerate Hermitian form nonsingular quadric palaeoxoic era plumbane saddle-type turret lathe seam orientation steel-cored wire rope tube boiler vernale zygocactuss