Hawaii's Natural History, in particular Big Island, is one of constant change in response to volcanic activity. The new lava is stark and is often a very hostile environment. The probability that plant life will grow quickly on a new lava depends on the availability of plant seed and water. Hawaii's plant life has evolved alongside volcanic activity and is able to start the process of developing and native forests in the nitrogen poor rock. The first tree of the Hawaiian forest to establish itself on the new lava is the ʻŌhiʻa Lehua Tree which can be seen scattered around the surrounding lava flows often with red "Tufts" type flowers.
Fig 1. ʻŌhiʻa Lehua Flower - The size of the plant can indicate the age of the flow
Most eruptions originate at the summits and rift zones of Hualālai, Maunaloa , and Kīlauea. Rift zones are areas where the volcano is rifting or splitting apart. The rock in a rift zone has many cracks and is relatively weak, and thus it is easiest for magma to make its way to the surface through these rift zones. Once at the surface, the lava flows downhill, following local topography. Like water, lava seeks the path of least resistance. Areas downhill of rift zones are more likely to be covered by future lava flows than areas on extinct volcanoes.
Fig 2: A Map of the Major Rift Zones, and recent lava flows on Big Island
From this location - Three Lava Flows are visable. The darker an younger lava flow surrounding this point is from the 1907 eruption and the lighter coloured lava down slope is believed to be 750 to 1500 years old the dark flow east of this location is from an 1887 eruption these three flows. All of these flows are from the pressure breaks in the Southwest rift of Moauna Loa (rather then from the Cauldera of Kilauea in Volcano N.P. itself).
To log the cache please answer questions 1-3, and send to the cache owner - then log your find with a unique picture for question 4 (I will contact you if there are any issues)
Go to the posted coordinates, You will see a flow from 1907 and a flow from about 1000 years prior.
1) compare two colours of lava flow stones - which is older?
2) Does the older flow seem to be more eroded and broken down? Is there more soil accumulation on the older flow?
3) Which Big-Island Rift zone did these lava flow come from?
4) WITH YOUR LOG - Provide a unique close-up picture with a stone from the 1907 flow, and a stone from the flow a thousand years prior. You may have to climb down into the flow to find the good ones!