TIGHAR
Amelia Earhart Search Forum => General discussion => Topic started by: Ingo Prangenberg on June 11, 2012, 06:51:30 PM
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Does anyone know if there will be further surveys undertaken in the northern lagoon area, especially in the main inlet where the "Wheel of Fortune" was spotted including the opposite side of the inlet where the school master and his daughter (separately) spotted large airplane parts?
Due to the currents, it appears as if, on numerous occasions, airplane parts have funneled into the main passage and into the northern lagoon areas. Although light aircraft materials can still be blown away during a torrential storm the lagoon should act as a sort colander, filtering out some light debris and depositing them in the northeastern/eastern lagoon coastline. What is blown away, might have been caught by the treeline, acting as its own filter for debris.
Budget wise, the lagoon is relatively shallow, thus making for an inexpensive search area compared to the deep. I wonder if a thorough search will be conducted again?
Does anybody have more information?
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I think it would really be interesting to fly the same sort of geophysics surveys we do for mineral resources. Since the search for diamonds went into full swing new techniques of HRAM survey (HIgh Resolution AeroMag) have become pretty commonplace. New sensors including EM and approaches can coax some pretty small targets out of the low level chopper EM over Mag data. Not the small stuff certainly but certainly things like fuselage and bigger bits would likely stand out well. You could cover a lot of area fast and things like surface terrain, surf and tides would not be a factor. While not able to give definitive data it might narrow the search some. It has probably already been considered though and I have missed it in the data search so far.
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Budget wise, the lagoon is relatively shallow, thus making for an inexpensive search area compared to the deep. I wonder if a thorough search will be conducted again?
I'm morally certain the answer is "not on Niku VII (http://tighar.org/Projects/Earhart/niku7.html)."
The big boat is meant to work in the open ocean.
I think that 95% of the effort will go into site mapping and spot-checking.
I would be very surprised if no one went ashore for a quick survey, but I doubt that there will be enough manpower and money to go back over the lagoon.
TIGHAR has done a lot with metal detectors and sonar in the lagoon itself and on the nearby shore. Some stuff was found, but none that was likely to have been from NR16020.
The land searches that I have heard discussed are:
- finish the work begun in "Rolling Thunder" at the Seven site.
- Search the village thoroughly (not a trivial task--much larger and more complex than the Seven Site).
- Search for Camp Zero (manageable for a 'regular' TIGHAR expedition)--if it is where TIGHAR speculates it should be.
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One of the reasons I have become very partial to the HRAM surveys is how quick they are and how detailed they can be. The edge of the reef would be essentially an afternoon once setup is complete. Now it would not be able to tell you what the targets are but depending on overall conditions some shapes are even able to be defined -ie if the large cross beam to wings structure was still intact. Won't be on this search but if something is found that proves the site it might be something to consider for down the road.
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... but depending on overall conditions some shapes are even able to be defined -ie if the large cross beam to wings structure was still intact.
My understanding is that magnetometers will not detect aluminium, so as the main wing spar is aluminium how will it be of assistance?
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To paraphrase Ric or Marty from sometime back, if someonw has the $$$ to donate to add these assets, I'm pretty sure that Ric will accomodate. Stuff like this is specialized, and can get expensive. Quite possibly with some planning it can be included in a future expedition.
Tom
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Regarding detecting aluminum, metal detectors and some magnetometers do have the ability, (such as those found at airports). If standard magnetometers do not detect them directly, a sizable chunk of aluminum should still "confuse" magnetometers and show up as an anomaly.
For more reading on specific magnetometers and their limitations look at: http://www.quantrosensing.com/ Price list included.
Besides it isn't so much the aluminum parts one would be looking for anyway. It is the accumulation of small bits of ferrous metal attached that cannot be replaced by an aluminum version. Those ferrous bits will add up and show a small scattered debris field.
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The survey system I mention is EM over Mag. Uses a dual sensor system to detect using magnetometer and electromagnetic conductivity meter.
EM will detect metals other than iron and as pointed out large chunks of other metals can show up as well to magnetometer though I was thinking more on the EM side. Salt water could be an issue. I know that EM surveys are done over salt water but don't know the ins and outs of it.
Not as a sales pitch or anything but the systems are quite often mounted on a local chopper. Like Tighar's helpful aerial survey chopper. Rented with operator and interpretation if required. My experience with them is on larger targets (kimberlite and some narrow vein precious metals also some discussion with the contractor re UXO - un-exploded ordnance) but it is amazing to see the cultural features that can be spotted on a survey. Utilities lines and things like buried car doors for instance - old road signs - all sorts of junk shows up in the oddest places.
I have filed this under my "sure would be neat to try" file and will leave it at that.
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Does anyone know if there will be further surveys undertaken in the northern lagoon area, especially in the main inlet where the "Wheel of Fortune" was spotted including the opposite side of the inlet where the school master and his daughter (separately) spotted large airplane parts?
Due to the currents, it appears as if, on numerous occasions, airplane parts have funneled into the main passage and into the northern lagoon areas. Although light aircraft materials can still be blown away during a torrential storm the lagoon should act as a sort colander, filtering out some light debris and depositing them in the northeastern/eastern lagoon coastline. What is blown away, might have been caught by the treeline, acting as its own filter for debris.
Budget wise, the lagoon is relatively shallow, thus making for an inexpensive search area compared to the deep. I wonder if a thorough search will be conducted again?
Does anybody have more information?
Your thought process is largely what drove the multiple searches of the lagoon over the years, particularly the 2001 and 2003 expeditions.
In 2001 we looked at the changes in the Delta of sand on the lagoon side of the inlet and metal detected out there extensively thinking that stuff washed in would then be buried under the growing sand delta. We actually brought a dredge with us, but never had enough reason to use it. We visually inspected the area along the face of the delta, and most of the bottom of the NE end of the lagoon using divers towed on manta boards behind a skiff. Everyone remembers where they were on 9/11, right? Walt and I were at the bottom of the lagoon most of that day wondering to ourselves what had happened to humanity in this world.
We've walked with metal detectors most of the shoreline directly across from the inlet thinking that would be a good place for stuff to get deposited. I am pretty confident that if there had been any large pieces of Electra out there, we would have noticed it, but I certainly can't be 100% sure.
The inlet has been extensively looked at with both eyeballs and metal detectors during the 2003 search for the "Wheel of Fortune".
The area of the lagoon just inside Baureke passage was searched with a magnetometer in 1999 (?)
Most of the lagoon was mapped by side scan sonar using an AUV during the 2010 expedition, and targets of interest were investigated by diving on them.
While we know that stuff can be flushed through the passage into the lagoon, as evidenced by a big tank from the NC that is on the lagoon shore, we've never been able to find any suspected L-10 related materials in the lagoon.
The lagoon is actually pretty clear of man made stuff, including NC debris, except for the area just off shore of the colonial village where domestic junk was discarded, and several 55 gallon drums filled with concrete out in the lagoon center that were used to map out the landing channel for the PBYs that supplied the Coast Guard Station.
So, with that history, there is no lagoon survey planned for the upcoming trip. Repeating any of that work would not seem productive given the other higher priority stuff that Marty mentions.
Andrew
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To paraphrase Ric or Marty from sometime back, if someonw has the $$$ to donate to add these assets, I'm pretty sure that Ric will accommodate. Stuff like this is specialized, and can get expensive. Quite possibly with some planning it can be included in a future expedition.
I've said it several times, in different contexts: TIGHAR has the manpower, expertise, and permissions to carry out operations at Niku. If there is a large benefactor who insists that a particular kind of search be done, I'm morally certain that TIGHAR will cooperate in organizing the mission. If, instead, all that is being offered is friendly advice, TIGHAR will take it under consideration as such. Opinions are like elbows--everybody has a couple of 'em.
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Re-directed from the "stills from the ROV" thread
Not sure if this is the best place for this question but it is relevant to the ROV search. Has any attempt been made to model the flow of water over and down the the reef? In particular I am thinking about the outflow from the lagoon after storms or high tides. The "landing strip" area is not far from the main channel and that flow should move materials on the upper reef during periods of drainage. I think the NC shelters the "landing strip" somewhat from the channel but it still may influence the distribution of debris down the reef face and may need to be taken into account in terms of the area to be searched.
Matt
Here is my impression. See photos below. Under normal tidal situation, the flow into the lagoon, highlighted as Green, comes through the Tatiaman passage and into the lagoon. A lot of the flow goes straight in, and then makes the right hand turn as it rebounds of the far shoe of the lagoon, which is why Taria point, that promontory that sticks into the lagoon from the far side, is there.
The normal outflow, highlighted as Blue, draws from all of the lagoon towards the passage, and disperses it seaward of the channel in all directions "north and south" along the reef flat. Since the ocean level is lower than the lagoon level, the water simply goes downhill wherever it can toward the ocean. The current can be pretty good right in the channel, but once it spreads out it isn't quite so strong. You can still walk around on the reef flat during an outflowing tide, so it isn't like it will sweep you off your feet. Also note that the water coming out of the lagoon is nearly 10° warmer than the surrounding ocean, so once it gets to the ocean, it is going to float on top of the colder ocean water rather than cascade down the reef face as you might imagine.
I don't see normal tidal flow as much of an agent of change with regards to moving big pieces of stuff around. That would more likely be reserved for waves and storm events.
Most storms evidently come with wind, and therefore waves, out of the NW. This "packs" water into the lagoon through the Tatiaman passage regardless of tidal condition. Enough packing, and the bowl overflows so to speak, spilling out both Baureke Passage, and also we believe down by the end of the lagoon where the CG station was - see the red lines.
You can clearly see that Baureke passage is open to flow in this 2007 sat photo, but it was high and dry in 2001, only marginally open in 2010, and evidently high and dry again in a sat photo taken most recently on 6/16/12, so it would seem that Baureke passage only once in a while serves a a relief valve for the lagoon. Note the vegetation pattern around Baureke that has some areas devoid of bush, this I think is evidence of the occasional over wash in this area, leaving a scar on the landscape, if you will.
After a storm, all that water left in the lagoon would again flow out the main channel, perhaps in a stronger flow than normal, but generally in an orderly fashion, so to speak, downhill in all directions towards the ocean. Again, I don't see this being an agent of change when it comes to moving big stuff around.
What moves big heavy stuff around on the reef are the waves and particularly storm related surf. Large amounts of water with major momentum is where the energy is to be found, and it generally pushes stuff shoreward and southward along the western shoreline rather than dragging it out to sea. See the second photo attached which shows the large blocks of coral, some as large as bulldozers, thrown up on the reef flat. You can also see the area from which they came, the broken edge of the reef with the rectilinear lines vs the softer surf lines. Note that the tide in this second photo is really low which is the only time that broken edge of the reef is above water. We've seen it at extreme low tides where the water from the reef flat is cascading over this edge in a little waterfall into the ocean.
None of this probably answers your question. I don't think we've modeled it beyond my description above as I don't think it was tidal outflow from the lagoon or a storm event that moved the Electra in our scenario. I prefer to see the rising tide on the ocean side, combined with waves, eventually floating the aircraft, either largely intact or in big pieces - definitely buoyant in comparison to NC debris or coral blocks - to the edge of the reef and beyond. After that, water infiltration, ocean current, "aquadynamics" (does an aircraft fly underwater?), and gravity do the rest.
The current off the edge of the reef generally heads to the NW along both sides of the island - see the Yellow lines, so if I were directing the deep water search I'd start N of the NC wreck, and work N to NW on the assumption that the aircraft, or big parts thereof, were floated off the reef by wave action and carried in that direction before hitting the bottom.
How long or far before hitting the bottom is another question, and you can find lots of threads in the Forum asking how long the Electra would float, whether or not it would be relatively intact or in pieces, etc. My personal thought is that it got floated off the reef mostly intact, perhaps without the landing gear and some of the skin, maybe some bigger parts torn off as indicated by the dado's coming ashore. Ric I think is more on the side of the aircraft getting beat up pretty badly in the surf and therefore not floating away particularly far.
I hope that helps.
Andrew
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Likeliest areas of initial structural failure, the thick black lines (apart from the landing gear being torn off).
These are the areas of the airframe that contain the highest percentage of void in comparison to airframe. Any forces acting upon the airframe, waves, tidal, storms etc... will have the most destructive effect upon the weakest part of the strusture, the part that contains the least airframe and most void.
These two areas contain the fuselage door opposite the skinned over window.
The two cockpit side windows plus the roof hatch.
Just my opinion
(http://)
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Andrew thanks that is very clear. I was concerned because I was reading a report about the oceanography of the reefs in atolls in the Marshall Islands
http://www.sprep.org/att/IRC/eCOPIES/Countries/Marshall_Islands/30.pdf
and some of the reef faces were described as have very turbulent , difficult currents. Of course none of those atolls matched the particulars of Niku but I see you all have been thorough and thought this through.
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Mee too---thanks andrew. Very informative from one that has been there. N-NW of the shipwreck----HUM----Probably where Ric will find the chunks of coral tht used to fly as NR16020---just trying to be positive! LOL
Tom
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Andrew,
You make a reference to new satellite imagery of Nikumaroro on 16 Jun 12 in your post above. Is there a link or source you can provide?
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Bill (I assume it is Bill Magnus, yes?)
I'll see if I can find out what is available.
Andrew
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Hi All:
I haven't posted to the forum in the past, but since this is a topic I've been so heavily involved in, I figured I should chime in here.
As the original poster noted, the lagoon has always been a tantalizing place to look, because if Electra debris has washed into it, it won't ever wash back out again. The lagoon is very shallow and so is searchable with relatively small and low-cost equipment, as opposed to the big (and expensive) gear that's on its way to Niku right now.
There have been at least 4 previous searches in the lagoon:
- In 1997 (IIRC) the lagoon area in the vicinity of Bauareke Passage was searched with some kind of magnetometer/ metal detector equipment gear set up in a skiff.
- In 2001 Andrew McKenna, Van Hunn and I spent about a week diving in the area between the Tatiman Passage sandbar and Taraia Point, which is the spit of land due east of Tatiman Passage. The reason for searching this area was that TIGHAR had collected anecdotes from colonists that there had been aircraft debris in the vicinity of Taraia Point. The results of the visual search were nada- the lagoon bottom in that area is very clean, and the silt is only, say, six inches deep or so, so large aircraft parts could not be buried in the silt.
Towards the end of the expedition virtually the entire team spent a day doing visual searching and metal detecting work in and around Taraia Point. Results were again negative. I ran a metal detector out to chest-deep water around the point, and only got one good hit- it turned out to be a porcelain-covered steel bowl, buried maybe six inches deep, in chest-deep water. Why this was at Taraia point is a bit of a mystery, but it did show that small metal objects could get buried in the silt there.
- In 2003 Van, John Clauss, Howard Alldred and I spent a day and a half doing an intensive visual search in Tatiman Passage for the "Wheel of Fortune". Other than an encounter with an adolescent blacktip reef shark being overly territorial, it was uneventful.
- In 2010 Jesse Rodocker, John Clauss and I worked in the lagoon whenever conditions were not appropriate for running the ROV in the ocean. We had an Iver 2 AUV fitted with a sidescan sonar that took a high-resolution map of probably 80% of the lagoon. We filled in the rest of the map by towing a Starfish 450 sonar behind a skiff. We reviewed the sonar data and Jesse and I dove on maybe 25 or thirty sites that looked interesting; all turned out to be coral heads.
So what would be appropriate to do in the future? Obviously the results of this summer's Niku 7 expedition will affect everything that takes place afterwards, so this is somewhat idle speculation. But I for one haven't given up on the lagoon- there doesn't appear to be any large- or even medium-sized airplane pieces there, but there could still be plenty of small pieces of aluminum there. Here's a plan that I would recommend:
- This summer John Clauss and I are going to be visiting White's Electronics in Oregon to talk with them about all things metal-detector related. Among the items on my discussion list are towed metal detectors that could be run around the lagoon, as well as metal detectors for finding large, deeply buried objects. We have spent a lot of time metal detecting on the Tatiman Passage sandbar, with largely negative results. But there is still the possibility that there is metal stuff buried deeper in the sandbar, below the detection range of our existing detectors.
- The lagoon sonar data from 2010 needs to be reviewed. We looked at the data while on the ship, but a review of the data in a more relaxed environment might turn up some areas that we want to revisit.
- If in the future we go back to Niku with a land team, and we get the OK to do some work in the lagoon, we should bring a search-and-recovery style high-frequency sidescan with us. The Starfish 450 unit we had in 2010 is a general-purpose unit and doesn't have the resolution needed to pick out small objects in the lagoon. Thus the inability to discern between coral heads and man-made objects. The sidescan data from the AUV is much clearer, but there are probably areas in that data that we would want to revisit as well.
Starfish now makes a much higher resolution unit, the 990, that is pretty much ideal for the kind of searching we are doing in the lagoon. So I'd bring a sonar like that, re-map all of the periphery of the lagoon (the areas that were done with the 450 in 2010), and revisit any areas of interest from the AUV sonar data.
- If towed metal detecting proves to be practical, spend some time in Tatiman passage and in the lagoon with the appropriate equipment.
- Spend some time on the northeast shore of the lagoon, NW and SE of Taraia point, doing some work with hand-held metal detectors out to chest-deep water.
Ehhh, that's about all my ideas for now. As they say, no plan survives initial contact with the enemy, so until the results of the deep-water search come in, it's pretty much idle musings....
-Walt
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Would you (reasonably) be able to use the same high-definition sidescan on the reef, if/when conditions are appropriate? I suspect that light aluminum objects that wash into the lagoon, might wash back out pretty easily, sometime over the years.
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Well no, not really. The Starfish sonar units are made for relatively shallow water, where you can dive as well. Since the visibility on the reef is amazing, a diver is going to see all kinds of stuff that a sidescan will not. The reason you're pretty much stuck with sonar or metal detecting or whatever in the lagoon is that the visibility there is so bad.
Below diveable depths, you need a different kind of sidescan setup. It's very hard to get close to the reef face without pranging your towfish against it. The current expedition is using an AUV to get in reasonably close, but even so it will be interesting to see whether they can get in tight enough to see small stuff. The sonar being used (an Edge-Tech 2200-S at 400 kHz IIRC) is not optimal for seeing really small stuff. If there's an Electra down there they'll see it. An Electra center section, sure, as long as there's not big rocks around. An engine, ehh, that depends upon what it's sitting on. Pieces of skin, likely not.
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Dave here is copied text from a post by Walt Holm in June
Re: The Lagoon as a Collection Basin (http://tighar.org/smf/index.php/topic,726.msg15258.html#msg15258)
« Reply #16 on: June 29, 2012, 12:55:02 PM »
Quote
Hi All:
I haven't posted to the forum in the past, but since this is a topic I've been so heavily involved in, I figured I should chime in here.
As the original poster noted, the lagoon has always been a tantalizing place to look, because if Electra debris has washed into it, it won't ever wash back out again. The lagoon is very shallow and so is searchable with relatively small and low-cost equipment, as opposed to the big (and expensive) gear that's on its way to Niku right now.
There have been at least 4 previous searches in the lagoon:
- In 1997 (IIRC) the lagoon area in the vicinity of Bauareke Passage was searched with some kind of magnetometer/ metal detector equipment gear set up in a skiff.
- In 2001 Andrew McKenna, Van Hunn and I spent about a week diving in the area between the Tatiman Passage sandbar and Taraia Point, which is the spit of land due east of Tatiman Passage. The reason for searching this area was that TIGHAR had collected anecdotes from colonists that there had been aircraft debris in the vicinity of Taraia Point. The results of the visual search were nada- the lagoon bottom in that area is very clean, and the silt is only, say, six inches deep or so, so large aircraft parts could not be buried in the silt.
Towards the end of the expedition virtually the entire team spent a day doing visual searching and metal detecting work in and around Taraia Point. Results were again negative. I ran a metal detector out to chest-deep water around the point, and only got one good hit- it turned out to be a porcelain-covered steel bowl, buried maybe six inches deep, in chest-deep water. Why this was at Taraia point is a bit of a mystery, but it did show that small metal objects could get buried in the silt there.
- In 2003 Van, John Clauss, Howard Alldred and I spent a day and a half doing an intensive visual search in Tatiman Passage for the "Wheel of Fortune". Other than an encounter with an adolescent blacktip reef shark being overly territorial, it was uneventful.
- In 2010 Jesse Rodocker, John Clauss and I worked in the lagoon whenever conditions were not appropriate for running the ROV in the ocean. We had an Iver 2 AUV fitted with a sidescan sonar that took a high-resolution map of probably 80% of the lagoon. We filled in the rest of the map by towing a Starfish 450 sonar behind a skiff. We reviewed the sonar data and Jesse and I dove on maybe 25 or thirty sites that looked interesting; all turned out to be coral heads.
So what would be appropriate to do in the future? Obviously the results of this summer's Niku 7 expedition will affect everything that takes place afterwards, so this is somewhat idle speculation. But I for one haven't given up on the lagoon- there doesn't appear to be any large- or even medium-sized airplane pieces there, but there could still be plenty of small pieces of aluminum there. Here's a plan that I would recommend:
- This summer John Clauss and I are going to be visiting White's Electronics in Oregon to talk with them about all things metal-detector related. Among the items on my discussion list are towed metal detectors that could be run around the lagoon, as well as metal detectors for finding large, deeply buried objects. We have spent a lot of time metal detecting on the Tatiman Passage sandbar, with largely negative results. But there is still the possibility that there is metal stuff buried deeper in the sandbar, below the detection range of our existing detectors.
- The lagoon sonar data from 2010 needs to be reviewed. We looked at the data while on the ship, but a review of the data in a more relaxed environment might turn up some areas that we want to revisit.
- If in the future we go back to Niku with a land team, and we get the OK to do some work in the lagoon, we should bring a search-and-recovery style high-frequency sidescan with us. The Starfish 450 unit we had in 2010 is a general-purpose unit and doesn't have the resolution needed to pick out small objects in the lagoon. Thus the inability to discern between coral heads and man-made objects. The sidescan data from the AUV is much clearer, but there are probably areas in that data that we would want to revisit as well.
Starfish now makes a much higher resolution unit, the 990, that is pretty much ideal for the kind of searching we are doing in the lagoon. So I'd bring a sonar like that, re-map all of the periphery of the lagoon (the areas that were done with the 450 in 2010), and revisit any areas of interest from the AUV sonar data.
- If towed metal detecting proves to be practical, spend some time in Tatiman passage and in the lagoon with the appropriate equipment.
- Spend some time on the northeast shore of the lagoon, NW and SE of Taraia point, doing some work with hand-held metal detectors out to chest-deep water.
Ehhh, that's about all my ideas for now. As they say, no plan survives initial contact with the enemy, so until the results of the deep-water search come in, it's pretty much idle musings....
-Walt
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Dave---We talked to Andrew and Walt at the symposium, and asked very similiar questions about the lagoon. What I can reall is there are place where a plane 'could' hace landed and survived. other places have jagged coral heads that are submerged that would do some pretty detructive damage to a fuselege of an aircraft. Seems I do remember reading somewhere on here that PBY's did sucessfully land in the lagoon in support of the loran station, although i may be mistaken.
Even though is seems like a good idea, not knowing what is under the surface would be weighing on my mind IF I were looking for a place to set th plane down. The beach, or the reef. might be better.
I think Andrew & Walt can speak better about the underwater topograpy of the lagoon, as well as the black tips.
tom
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Just to add to this discussion, the only object i know to have survived the journey from Nessie and Norwich City area, into lagoon is the water tank, which ended up not far from the seven site :)
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Amelia's lively hood, depended on the Electra making the round the world flight, The cost of fishing the Electra out the lagoon is not worth thinking about, MY opinion is if they could land safely on reef, they had a chance of refueling an taking to the air again to howland.
Also if they landed in lagoon they would have no chance of radioing for help, So i think the pluses of a reef landing out weigh the lagoon landing theory.
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Walt brings up some really good points. Points that come from someone that has BEEN THERE, and knows the territory. It occured to me the the 'standard' metal detection, and sonar devices just might not be appropriate for this island. The reef slope topography shows this. I assume the lagoon is similar with coral heads, and other things that we dont know about.
Perhaps, a group of those members that have been in the lagoon, like Walt and Andrew, could get together with Whites, Phoenix, or others, and come up with something that serves the purpose. Obviously, you cant build one piece of equipment that handles all possibilities, but maybe they can.
The lagoon 'could' hold other secrets that we arent aware of. IMHO, we should search it too.
Tom
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Tom said
The lagoon 'could' hold other secrets that we arent aware of. IMHO, we should search it too.
I agree that the lagoon bears further scrutiny.
I hope this isn't too dumb a question, but if there were bones swept into the lagoon, how could they be discovered? By dredging? The naked eye? I can't see a metal detector helping unless there is metal in a tooth :)
Gloria
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I hope this isn't too dumb a question, but if there were bones swept into the lagoon, how could they be discovered?
Bones would probably not survive in water.