Meyer Lake is a shallow pond covering 8.4 acres (3.4 ha) on the northern part of the island of Molokaûi, Hawaii. It is primarily fed by surface runoff and submerged springs and is located south of Kalaupapa at an altitude of 2,000 ft (610 m). The lake is named after Rudolph Wilhelm Meyer.
The lake occupies a shallow depression on the andesite lava of the upper member of the East Molokai Volcano, at the southeastern foot of Puûu ÃȈ Âlelo cinder cone. It is a perched pond, held at that level by impermeable underlying andesite and weathered soils. It takes runoff water from a surrounding catchment of approximately 100 acres. A small dam about 6â¯ft high has slightly increased the pondâÂÂs capacity. The depth varies seasonally but has been recorded as being no greater than 5â¯ft. The pond area ranges from about 8.4â¯toâ¯10.3â¯acres depending on the water stage of Molokaûi.
The soils surrounding Meyer Lake are highly weathered tropical soils with a high content of iron oxide and humic substances characterized by a lack of distinct soil horizons. The soil is classified as belonging to the ferruginous humic latosol group and has accumulated iron and titanium oxides near the surface, forming titaniferousâÂÂferruginous laterites. These soils typically form in regions with alternating wet and dry seasons and often show concentrations of iron and titanium oxides, sometimes forming concretions, in the surface horizons. The process of laterization occurs when silica is leached out while iron and aluminum are concentrated.
Between 1952âÂÂ1953, shrubs such as guava were cleared for pasture improvement, exposing areas of extremely high titanium content. Indurate, dehydrated soil areas are grayishâÂÂpurple in color, in contrast to the reddish-brown surrounding soils. These areas contain numerous magnetic ferruginous concretions, indicating movement and redeposition of iron by percolating water. Erosion also transports soil aggregates to the foot of nearby slopes.
Chemical analyses have measured high iron oxide (~74%) and titanium oxide (~21â¯%) in the concretions. Along the shoreline these have lower titanium content but high iron oxide, reflecting sediment sorting and accumulation by wave action. Studies of molecular ratios suggest that titanium oxide increases with dehydration of the soil, while ferric oxide accumulates in the hardened concretions.