Huge Offset Side Branches Serve as Mass Dampers To Help Hyperion Redwood Grow Very Tall Without Wind Breakage

1      Structure of Hyperion Redwood

 

The overall structure of Hyperion redwood is well detailed in this excellent redwoods study (as SESE 49 in Appendix K):

How do tree structure and old age affect growth potential of California redwoods?

Stephen C. Sillett, Robert Van Pelt, Allyson L. Carroll, Russell D. Kramer, Anthony R. Ambrose, D’Arcy Trask

Ecological Monographs 2015 Vol: 85 (2) :181-212.
doi: 10.1890/14-1016.1

I use this study for some reference information but what follows are my own independent analyses and ideas.

Hyperion has a very unusual feature versus other very tall redwoods in the study.  About 30 meters up on the tree there are two huge branches that grow out from the trunk at near 90 degree angles for a couple meters and then turn straight upwards for twenty or so meters.  Both these branches are on the same side of the trunk and together weigh about 5,000 kg.

Hyperion has a volume of 550 cubic meters, of which about 140 cubic meters are above the huge branches growing out from the trunk thirty meters up.  The 140 cubic meters of volume has a total weight of about 55,000 kilograms (based on Hyperion’s total mass of 210 Mg and total volume of 550 cubic meters).

Therefore the upper 85 meters of Hyperion can be viewed as a 55,000 kg object with 5,000 kg of weight offset from but connected to the base.

 

2      Mass Dampers

 

Mass dampers are used in construction and design to help stabilize vibration from external forces.  For example very tall buildings will employ mass dampers to reduce sway so people do not feel sea sick in high winds as the top of the building sways.   Dampers are also used in automotive engines to reduce vibration.

Mass dampers add cost and complexity to structure design, and there is a trade off in materials and methods used in vibration dampening versus actual benefit.

As a result typical mass dampers are set up in a counterbalance system where the damper is about 10 percent of the mass of the object being dampened.  This then reduces vibration at the radial end of the vibrating object by about forty percent.

For more information see Wikipedia article on Tuned mass dampers.

 

3      Hyperion And Its Built In Mass Damper

 

Reviewing the redwood diagrams it is evident Hyperion redwood has very little breakage in its crown for such an old and tall redwood tree (1260 years old, 116 meters height).  There is no breakage in the top part of the crown, this is one reason why Hyperion has its great height.  Great location, great soil, nightly fog, and tucked into a valley for wind protection.

But Hyperion has something else going for it.  Those big side branches 30 meters up, with combined weight at ten percent of the trunk weight above them, serve as tuned mass dampers to reduce crown sway in high winds by about fifty percent.   The unique structure of Hyperion has contributed to wind breakage suppression, allowing Hyperion to grow very tall without interruption.

Thanks for reading.

Looking up Hyperion’s trunk from uphill side.  Hyperion’s large , low side branches are not shown in this photo.

Humboldt Redwoods State Park – 1,000 100 Meter Redwoods

1      100 Meter Redwoods

 

What sets coast redwoods apart from other tree species is their great height.   It is the only species with extant trees over 100 meters in height, and there are 3,000 – 5,000 such redwood trees.  And around 1,000 of these trees are in Humboldt Redwoods State Park (HRSP).

The 100 meter redwoods in HRSP are of course concentrated along Bull Creek and nearby Eel River groves.  But surprisingly there are 100 meter redwoods in many areas of Humboldt, from the very northernmost area to the very southernmost area.

A 2014 Eel River LiDAR survey generated point cloud data which can be used to determine tree height by subtracting ground heights from first return heights.  There is existing software with built in functions to do the heavy lifting.  The point cloud data was recently put on the Open Topography Portal.  I went ahead and downloaded twenty of so subsections of this point cloud data and reviewed tree height in the groves along the Eel River and Eel River south fork.

As part of the review derivative maps were created which profile the canopy by height.  For example, this is the road going into Founders Grove from the Avenue of the Giants.  The purple indicates 100-105 meters in height.  You can see there is a 100 + meter tree at the entrance, then another taller one on the right side of the road right where the parking lot starts.  So this level of specificity can be reviewed throughout the park.

Founders Grove entrance canopy map

 

This table is a tall tree recap of the areas of Humboldt Redwoods included in the 2014 LiDAR survey.  Most have 100 meter trees, some quite a few.  I also included a column for the number of trees between 90 and 100 meters.  To do this work I just counted  crowns by height band on the derivative height maps I created.  The counts are approximately right but I am sure could be off by a little bit (but not by much).

Eel River Corridor HRSP Tall Tree Summary

 

Rather than showing the derivative maps I made four overview maps of Humboldt Redwoods.  I hope you enjoy them, they provide a good general overview of where the tall trees are.

2      North End – Pepperwood Area

 

The Pepperwood area has a few 100 meter trees, including one that is quite tall.

HRSP North Areas with Tall Trees

 

3      Core Area

 

Most of the tall trees in Humboldt are along Bull Creek or in the river groves near the Bull Creek outflow.  Although Bull Creek was not included in the 2014 LiDAR survey, there are other sources for that area with partial information.   So the counts for Bull Creek are estimates.  There are also quite a few tall trees along the river south of Bull Creek.  Then Founders Grove, Rockefeller Loop, and Federation Grove have many tall trees.

HRSP Core Areas with Tall Trees

 

 

4     Burlington to Canoe Creek to Great Peninsula

 

Here there is a large cluster of tall trees along the Canoe Creek bend and along Canoe Creek itself

HRSP South Areas with Tall Trees

 

5      Phillipsville Area

 

Here way at the south end of the Avenue there are still a few tall trees.   Also not shown is the Redway area, where there is one 100 meter plus tree.

HRSP Phillipsville Area Tall Trees

 

 

Doing these maps has me interested in visiting some areas of Humboldt I have not been to.  One trail in particular is the River Trail from Bull Creek south to the Garden Club Grove.  It is supposed to be very scenic.

Thanks for reading.