Thursday, February 19, 2015

Water in the Desert - Historical Comparison

Desert hiking offers a lot of great benefits - dry weather, few bugs, beautiful open views - but makes up for them in the challenge of finding water.  On the PCT, I was essentially spoon fed water information from the water report.  Hikers ahead would text message a trail angel with the status of water sources, listed by mile number, who would then update the website so it could be printed in the next town.  Libraries and popular trail angels caught on and offered a stack of pre-printed water reports from that week.  You didn't even have to print them!  This kind of certainty makes hiking in the desert and water caches largely unnecessary since you almost always know what to expect ahead.

The AZT, and CDT both have online water reports but they are updated much less frequently than the PCT because there are far fewer hikers.  Much of the latest information on the "current" AZT water report is from April of 2014. Arizona has experienced an entire monsoon season and most of a winter since then! Instead, it helps to look at the historical data and compare to previous years.  Fortunately the trail associations for the GET and AZT maintain a list of historical water reports.  I can't seem to find one for the CDT but the Ley maps make notes of when sources ran dry and last years water report is still up.  I think this is because most water sources in NM on the CDT are man-made from cattle ranchers and don't vary as much as the streams and springs found on the AZT and GET.

Anyway, for the AZT and GET the problem lies in figuring out what year in the historical database your hiking year is most similar to.  This is more easily done part way into the hike once you've noticed what's running and what isn't, but at the beginning it can be a guessing game.

Here's the historical report for the southern portion of the AZT:

Water sources are listed by mile from the southern terminus with a brief description and reliability rating from 1 to 4, with 4 being always reliable.  The next set of columns indicate whether a source was running (x) or dry or no information (blank).  A brief look shows 2005 as a very wet year (the note reads "water almost everywhere" with 2006 and 2003 as especially dry years.  

Next we have to figure out how those years compare to 2015.

Fortunately the libertarians have yet to completely eviscerate the federal government and there is an enormous amount of publicly available data from the US Drought Watch. You can select individual states and get reports from the current month back to January 4, 2000 for Arizona.

Let's see how we're doing in 2015:


The AZT runs roughly north from the bottom center corner of the state.  If I had a GIS program, I could import those layers and a GPS track of the trail but that's going a little more in depth than we need.  

Arizona gets most of its water in the summer monsoon season (July through September) and the winter months (December through March) so things are more likely to improve than they are to get worse for my start on March 16th.  

Now let's look at some previous Arizona Data: 


2014 looks like it was an especially dry winter and the graph for April 1st (not shown) doesn't look much different, so sources running for spring 2014 hikers are most likely running now but using that model may be too conservative.  Instead, I looked through the years for the historical report, the most similar looking year for the approximate trail corridor is actually 2007:


Just to check our method, let's look at 2006 - a dry year from the historical water report:


Looks dry!

From this, we can guess that most sources in the historical report for 2007 will be similar in 2015, and that anything running in 2014 will likely still be running in 2015.  That way if the water report isn't updated I can still estimate when the next water will be (although I still plan on updating the water report as I go for anyone behind me).  

We can do a similar exercise for New Mexico on the CDT - this is the current drought map:




This looks wonderful compared to 2013:


For comparing with the water information from last year, we're still looking better:


I estimate I'll be entering NM on the GET towards the end of April and a lot can change between now and then but we can draw similar rough conclusions as with the AZT water.


Wednesday, February 18, 2015

Warm Feet in Winter

Hiking in New Hampshire winters means dealing with extended exposure to everything from below zero temperatures and high winds in dry snow and solid ice to above freezing temperatures and slush in the tail ends of winter or during the occasional thaw. In this post I'll try to give you an idea of what I've discovered over the last few winters on how to keep your feet warm.  Notice I don't say warm and dry, since foot sweat will inevitably wet any insulation.

In order to figure out how to keep heat in, we have to understand how we lose it through our footwear.  I'll try to go light on the thermodynamics but a basic understanding is essential.

Heat Transfer 


Conduction is the loss of heat through your insulation.  If the air temperature is 0 degrees and your feet are about 96 degrees F, the difference between the two creates a gradient - like water going down a stream from a higher point to a lower point.  You can imagine a thicker sleeping bag as a slower stream since the difference in temperature is spread across more insulation. A lower outside temperature also makes a steeper, faster stream and we lose heat even faster.

Most insulation we use for hiking boots like primaloft or thinsulate relies on small fibers to trap pockets of air and prevent heat from escaping since air is a natural insulator.  Dry air and dry fibers resist losing heat through conduction extremely well, like the insulation in your house.  Water, such as the water in your sweat, transmits heat efficiently - about 25 times more than air.  When the two mix, we lose a lot of insulation value and transfer much more heat through our footwear. 

Convection is loss of heat due to the movement of air or another fluid like water, so if our footwear is too loose causing air is being pumped due to the movement of our feet we will feel cold.  Convection is how we can describe feeling a draft, a cold burst of air pulls heat away from our body and runs.

Radiation is heat transfered by warm bodies emmitting photons, it happens with all matter above absolute zero.  We gain heat from the sun through radiation but also from anything hotter than us, like stale chicken fingers under a heat lamp.  Our feet actually lose some heat to radiation, though it's not as significant as conduction and convection.  The bigger the difference in temperature between two surfaces (with an air gap) the more heat loss from radiation.  Some companies add a reflective liner to clothing but in order for that to work you need an air gap between us and the reflective layer and a very high temperature gradient between the reflective layer and whatever is next to it.  I haven't noticed any significant difference with this technology, though you can see how it would work in a space blanket.  

Phase Transitions cause heat loss or gain, depending on the phases.  For instance, it takes 4.2 kilojoules (a measure of energy) to raise one liter of water one degree Celsius but 2270 kilojoules to transform that liter of water to vapor.  A more relevant comparison would be 155 kilojoules to raise 1 liter of water from ice cold to body temperature, then almost  15 times more energy to evaporate it!

This is why we get so cold in wet clothing, part of our body heat is causing the water to evaporate which takes an enormous amount of energy.  Melting snow or ice with our bodies, such as eating it, also uses an enormous amount of energy. 

From this very basic understanding of heat transfer we can glean a lot of information about how to keep our feet warm.  We know that dry insulation prevents conduction many times better than wet insulation.  We know it takes nearly 15 times as much energy to evaporate water than it does to raise it to body temperature and we know we can lose a great deal of energy from the movement of air.  We also can see that reflective linings only work in very specific situations and not in the cramped confines of a boot.  For more information see: http://en.wikipedia.org/wiki/Heat_transfer   

We also need a basic understanding of how our bodies regulate temperature.

Cold Feet!


If part of us is too hot, our skin will sweat.  This is because our bodies have evolved to take advantage of the loss in energy from sweat evaporating into the atmosphere.  Conversely, our feet and hands rely on warm blood flowing from our core to regulate their temperature.  If our feet get too cold, the blood vessels constrict, reducing blood flow.  This is to keep our core warm at the risk of losing our extremities to frostbite.  

The combination of heat transfer and our bodies reaction to cold and warm creates the most common cold-feet scenario - over insulation, followed by sweat, followed by cold feet that just won't warm up.  Our feet start out too warm or get too warm from periods of high activity like hiking uphill, so they sweat to cool down.  The sweat slowly wets the insulation faster than it can either wick somewhere else or evaporate through the "waterproof-breathable" boot shell.  Even if our boots were very breathable, we would now be losing even more heat due to the phase transition of water! Breathable or not, the liquid water reaches the inside of the boot shell and acts as a conductor for heat to leave our feet and enter the atmosphere since the insulation is no longer dry and full of air.  Now our feet can't stay warm enough, so our blood vessels constrict and we feel even colder!  Ironically, the most common reaction to this situation more insulation, which just adds more space to water to collect before the boot gets cold.  This actually works for many people if you pull your sweaty feet out of your boots at the end of the hike and never had cold toes.  

This is because are inclined to over prepare for things we fear most, so many of us will take extra insulation thinking it's needed to stay warm.  You see this all the time with new winter hikers that start out in too many layers, sweat our their insulation and get cold not realizing they should wear less while hiking hard and more when stationary or going downhill.  It's a big turn off to winter hiking if you start thinking there's no way to stay warm even with all that insulation!  It's also very easy to sweat without realizing, especially in your footwear. For our core we can take layers on and off very easily but no one changes their boots out when their feet are sweaty!

So how should we keep our feet warm?  To me, there are four things that will cause cold feet (assuming the our core is warm), and each can be prevented.

Cold Legs


If the blood flowing to your feet is cold, they will be even colder.  Add a shell over your hiking pants or knee high gaiters over your calves to keep the blood going to your feet warm.  If you notice your legs are cold when your feet are cold, this is your most likely problem.  My gaiters enable me to wear "waterproof" un-insulated trail shoes into the 20's and still keep my feet warm.  Knee high socks will also help since you likely don't need as much insulation on your thighs which are thicker and closer to your core.

Restricted Blood Flow


If your boots are too tight because you stuffed warmer socks in them your feet won't get enough blood to stay warm.  If you pull your cold feet out of your dry boots and socks but your legs are warm, this is the most likely problem.  Size your winter boots on the loose side to allow for thicker socks.  I prefer a lighter insulation on my boots and thicker socks since you can change out wet socks mid-hike but not wet boots.  You can also wear thinner socks for warmer temperatures and tighten the laces to take up the extra space without needing another pair of boots. However, if the boots are too loose we'll lose heat through convection - air moving in and out of the boot. 

Another tip for cold toes is to swing your feet or kick the air to force blood through them faster. This also works for your hands - swing your arms to a sudden stop to move warm blood through them.  If you're sitting at camp or on an extended break, sit with your feet closer to your heart's height so there's less resistance for the blood to work against.   

Dehydration also restricts blood flow by thickening the blood and can be common in winter when hikers don't want to stop to drink.  Monitor your pee color and frequency, though I find snow makes pee look more yellow than normal.  

Wet Insulation


This is what I've spent the most time talking about, so hopefully you've got it by now.  The insulation gets wet, transfers heat and evaporates water leading to cold feet.  The problem is we go from hiking hard up hill to standing around at the summit or at camp to hiking easy downhill all in the same boots.  You can change into dry socks if the conditions allow and if you have any.  Alternatively, vapor barrier liners (VBL's) work to prevent sweat from entering the insulation.  In very cold temperatures or if I intend on camping, like at my 48 finish, I wear a ham roasting bag from the grocery store over a thin liner sock under my wool sock.  The combination fits snugly in my boots and keeps my insulation from getting wet.  My feet still sweat and get wet but at least they're warm!  

Lack of Insulation


I saved this for last since I really think it's the most unlikely situation in NH winters if you're already wearing warm socks and any kind of insulated boots.  However, if you have Raynaud's - a lack of blood flow to hands and feet - this is probably your problem.  If your legs are warm, your feet are not restricted in your boots and your socks are not sweaty at the end of the hike - you need more insulation.  Look for boots with 400 grams of thinsulation vs. the usual 200 or with (meaningless) temperature ratings of -40 or lower. You can also size your boots up for fitting chemical toe warmers in there, which generally last most of the duration of a day hike.  

Conclusion


So you know understand how we lose heat and the most common causes of cold feet.  Hopefully I've solved some footwear problems for you, at some point I'll do a more specific post on types of winter footwear but those are the basic principals.  Let me know if you have any questions in the comments!



Wednesday, February 11, 2015

Overnight to Moriah and my NH 48 4k Finish

For whatever reason, hikers in New England seem to love to hike lists of peaks that make some criteria.  I just finished the first list most people do, the 48  4,000 foot mountains in New Hampshire but there are so many more - the 67 New England 4,000 footers, the 100 highest peaks in New England, the 3,000 footers of NH, the "52 with a view" etc. The defacto king of the lists is "The Grid" where hikers attempt to hike each of the 48 at least once per calender month for a total of 12 x 48 = 576 peaks.  Based on my conversations with other hikers, this obsession with lists is not the case for any other places around the country and don't know why.  I think it's a combination of the typical driven career type and our own need for classification and accomplishment.  It could also be a far more accessible miming of mountaineers obsessed with climbing the world's 8,000 meter peaks. It could also just be the result of a group of people with limited options who have been hiking the same areas for years trying to seek out new experiences; the lists offer an easy resource for people looking for new places to hike or a reason to hike the same peaks over and over again instead of the ambiguous "hike it because it's there".

I started hiking in the Whites when I first moved to New Hampshire in 2010, just the occasional summer day hike when I wasn't mountain biking.  Over the next few years I started doing more hikes, including a winter skills weekend at Cardigan with the NH AMC chapter.  Eventually I heard about the NH 48 and started a mental tally of what I'd done but still returned to the same mountains that I liked to hike over and over again or that friends suggested.  Moving to Boston lead me to becoming an AMC co-leader and doing more hikes up north than I had been with the lack of good local mountain biking and my sudden hiking fitness from the PCT.  I realized I only had something like 15 or 20 mountains left and figured why not just do them all.

I still feel weird about the accountant-like nature of keeping lists but it makes sense if your main activity is hiking, you are geographically limited and like to hike with fellow peak baggers.  I'm not knocking the practice, I just find it odd.  There are parallels between through hiking and peak bagging, mainly the common experience between people who have hiked the same trails or bagged the same peaks and the connection that offers.  Maybe it's that common connection that we seek out with other people that drives the peak baggers?

Anyway, that was a long rant for the start of a trip report.  This was my Facebook event description:

People keep telling me this is a big deal so now it's got a facebook event! Saturday we will hike up the Stony Brook trail, give Moriah the middle finger and camp about 500' lower on the Moriah Brook trail. There, fires and improvised shelters will be made or you could bring a tent. Sunday, we'll hike back up the ridge and meet Pam Wilmot and anyone who doesn't want to set things on fire/sleep outside and hike up to the Summit. Then out the Carter Moriah trail to a car spot (possibly).

Philip Werner and Guthook came along for the overnight - their trip reports are here and here and I stuck my photos on dropbox here.  Philip had been wanting to try winter fire building in earnest which means dedicating most of a day to collecting and processing wood.  It was definitely a learning experience.  We got started around 9 am after I dropped Pam off for an AMC hike on the Carters (just down the street) and took our time getting to camp, about 200 yards down the Moriah Brook Trail and a little ways before we lost the trail entirely in deep snow and bent over trees.  The campsite we settled on seemed ideal - largely level with big open areas surrounded by trees with plenty of down wood to choose from.

Philip set to work gathering wood as Guthook and I dug the fire pit down to bare ground.  We hit a thick layer of ice from a rain storm last fall about 2 or 3 feet into the fluffy powder which almost destroyed Guthooks Costco metal "avalanche" shovel and stopped my plastic avalanche shovel entirely.  This layer stopped me from digging a real snow cave so I just set my tarp over a shallow depression in the snow under the cover of a tree.  We got through that and hit bare ground another 2 feet down.   The ground was covered in moss - our first red flag for our fire plans.  Around this time Siren stopped by on a test hike of an HMG pack.  It must have been funny for her to suddenly find three grown men cutting wood and playing with knives in the middle of the white mountains.

Philip came back with some wood and we all took turns gathering, cutting and splitting with the Mora knives Philip lent us with long stretches spent melting snow for water (mostly by Guthook).  You can use a sturdy knife like a wedge by setting the blade on the top of a cut log and wacking it with another log - a process called batoning. We made some larger kindling this way and stacked the biggest logs on the ground.  Philip and I were both keen to try an upside down fire where you build a fire on top of the larger pieces and the coals burn down to start them on fire.

Unfortunately all the big down pieces of wood were wet and frozen solid so they had to melt, then dry before burning.  I'm certain this is because we chose an open boggy area that is too wet to allow even dead wood to dry before freezing in Fall.  We were unable to get anything larger than thumb sized to light and even that was a struggle.  Towards dusk, we decided to give up on the upside down fire and switch to a log cabin formation on top of the bigger pieces of wood.  Even that didn't work!  The split pieces along the sides of the "cabin" just wouldn't light.  We gave up around 7 pm and just used the white gas and inverted canister stoves Guthook and Philip brought along for our dinners.  I managed to barely cook the Italian sausages I brought over the fire as well but had to boil one when it was under cooked.

As if on cue, Guthooks white gas stove broke after he mentioned how reliable it was and how many winter trips it had saved.  The siphon had popped out of the valve that screws into the fuel bottle and was floating around in the bottle, just out of reach.  We debated how to get it out and settled on dumping the fuel out into my pot to get the siphon.  Guthook repaired the stove and we were back in action but surprisingly low on fuel the next morning.  We easily used 20 ounces of white gas and an entire canister from Philip's stove.  For 3 people melting snow over 24 hours that's a huge amount!

Around 8 pm we called it a night and got into our respective shelters - Black Diamond First Light tents for Philip and Guthook and a 5x9' tarp for me. It had started snowing that afternoon but there was virtually no wind at camp.  However, the light fluffy snow will find its way under a flat tarp with the tiniest of breezes and I quickly felt snow flakes melting on my face.  It had been lightly snowing all day and was predicted to continue snowing into the next night.

Getting out of your sleeping bag in 3 season camping is annoying, but not a big deal.  In winter, it's a real pain in the ass.  You have boots that need to be kept dry even though it's easy to post hole wherever you walk, and you freeze your butt off in a hurry without putting all those layers back on.  Fortunately my -20 degree REI sleeping bag stays warm for quite a while with the help of a hot water bottle so I could dive back in and warm up quickly.  Still, I first got out and lowered the tarp pitch, then off with the boots and back into the sleeping bag.  No luck, still a few flakes were coming in from over my head.  In desperation to avoid getting up again I set up the 1.5'x4' sheet of Reflectix Guthook had given me to use as a fire reflector like a little wall behind my head and that blocked the snow until the sub 1 mph breeze switched directions and snow started coming in from the side.

I then managed a feat of contortion that only the most experienced and laziest of winter backpackers should attempt - flipping 180 degrees around under a tarp pitched less than 2 feet off the sloping ice covered ground.  At that point my face was protected by the closed end of the tarp, the sleeping bag was protected by my bivy and I slept comfortably and warm.  Until I had to pee about fifteen minutes later...

The next morning we fired up the stoves again and started heating water for the hike out.  Philip ran out of gas but we had just enough in Guthooks whisperlite to get us set up for the day with pine and smoke scented hot water.  We thought about the fire, but were out of easily accessible tinder and kindling so Guthook scattered the logs and I helped him fill in the pit with snow as the snow storm started to intensify.

A few minute before 10 am I hiked the 200 yards back up to the trail junction and our meeting spot and almost immediately saw Pam, Siren and Matt coming up the trail.  Perfect timing!  We said our hellos, assembled the group and headed up to Moriah.  The 1.6 miles went slow with all the breaks for layering and the drifted trail, but we finally made it to the base of the summit scramble. I thought we needed goggles at one point but only the first two of the five or six exposed ledges were windy, otherwise the hike up was calm until the summit. Everyone went ahead to make a little NH 48 ceremony for me in the windy exposed ridge, took some photos and butt slide back down to the trees.  We had champagne and some excellent brownies both brought by Pam (thanks Pam!) and headed back out to the car.

The hike out was more fun since the hard part was behind us and everyone got a chance to chat and joke.  It was a great group and I was amazed at how well everything fell into place, despite the lack of roaring fires on Saturday.  In the future I'll pick a campsite further from wet areas and stick to tepee fires to dry out the inevitably wet wood found in eastern forests.  I'll probably bring a shaped tarp too...