multiple volcanic island summits over 1000 and
2000 m (Kauai, Oahu, Molokai, Lanai, Maui,
Kahoolawe, and Hawaii) and with more emerged
land than ever. Only some 1.2 million years ago,
the now separated islands of Maui, Lanai, Molokai,
and Kahoolawe, as well as the Penguin Bank
seamount, constituted the Maui-Nui complex (‘Big
Maui’ in Polynesian), an island larger than the cur-
rent island of Hawaii, which was divided by subsi-
dence some 0.6 Ma (Price and Elliott-Fisk 2004).
The Maui-Nui complex has been reunited several
times by sea-level falls associated with Pleistocene
glaciation. This increasingly well-specified envi-
ronmental history has considerable relevance to
understanding the biogeography of Hawaii, as will
be discussed in later chapters.Jamaica
Several of the themes of this section are well illus-
trated by Ruth Buskirk’s (1985) analysis of the
history of Jamaica in relation to the rest of the
Caribbean. The changing configurations of
Antillean land masses during the Cenozoic, as
suggested by a variety of authors, are presented inENVIRONMENTAL CHANGES OVER LONG TIMESCALES 31Kure
(29.8 Ma) Midway
(28.7 Ma)Lisianski
(23.4 Ma) Laysan
(20.7 Ma)
Gardner
(15.8 Ma)
LaPerouse
(12.8 Ma) Necker
(11.0 Ma) Nihoa
(7.3 Ma)Hawaii
(0.5–0 Ma)Maui Nui complex
(2.2–1.2 Ma)Oahu
(3.0–2.6 Ma)Kauai
(4.7 Ma)
Niihau
(5.1 Ma)(^02004006008001000) km
pre-subsidence
subaerial
volcanic shicld
sea surface
break-in-slope
post-erosion
rock outcrop
submergence/atoll
break-in-slope
post-subsidence
Direction of plate
movement
coral cap
H1
H1
H1
7 ̊
7 ̊
D
D
D×tan 7 ̊
S
H2
1
1
3
3
2
2
4
4
Figure 2.12Features of the Hawaiian ridge, life stages of volcanoes, and estimates of island altitude over time. The main islands are detailed in the
inset. Ages are given in parentheses for selected volcanic peaks. The numbered sequence of boxes depicts life stages of islands and associated
features used to estimate life histories. (1) The break-in-slope, marking the maximum shoreline of a volcano as it formed, is depicted by a black
outline on the map. (2) The depth of break-in-slope (S) indicates the amount of subsidence that has occurred since shield formation; the present
elevation of an uneroded volcano (H2) is then added to determine its original height (H1). The original height can also be calculated by using the
distance from summit to shore (D) and assuming a 7angle. Summits of the main islands are shown as white dots on the map over the island areas
shown in black. (3) Slower subsidence and erosion reduce volcanic peaks to sea level. Four rocky islets (filled triangles on the map) are near the end
of this stage, with the amount of erosion (E) estimated. (4) Finally, with no more rock above sea level, only seamounts (black dots) and small coralline
islands (open triangles) remain (Redrawn from Price and Clague 2002, Fig. 1).