Note: This page is still a work in progress and may be missing sources.
What is HAARP?
A premier facility for the study of ionospheric physics and radio science located in Alaska. Or so says its official website...
An overview of earthquake weapons and top secret military technology
It's possible that the US military has developed or is working on building earthquake weapons or some kind of weather modification technology. But at the moment, the best weather modification technology that we have evidence of is cloud seeding, which hasn't been perfected. Just because some one believes there are such weapons it doesn't give them the right to misquote military officials or to make stuff up. An example of what conspiracy theorists do is claim that scalar technology was invented by Tesla or by some fringe physicist and that it has been suppressed and thus used for secretive nefarious purposes.
This is an extraordinary claim and I think its one we can investigate. There is the chance that the military successfully covered up every shred of evidence and has intimidated physicists around the world into keeping a big secret, but I don't find this plausible. They'll have to do better than that. How is it that not one scientist has independently discovered scalar technology since the 1930's? And even if the so called "scalar waves" were discovered more recently, you would still expect someone else independently discovering it somewhere else in the world. This is a nobel prize worthy discovery, yet there isn't one scientist who has come forward about it. So what else can we infer from other historical and scientific facts,on how plausible these claims regarding HAARP are?
A few quick points about HAARP
It often seems that HAARP CT proponents make it out to be far more mysterious and secretive than it really is. This is probably because they don't understand what HAARP is. HAARP has an annual open house tour, where scientists and the laymen can ask questions and get an idea of the research that is being done there. There are also 12 universities that send students there to do research in ionospheric physics. (1)
I would find it hard to believe that all of the scientific journals and research from HAARP was all fabricated, and thus I conclude that they are doing ionospheric research there. But what are they doing exactly? And could they be doing other secretive research?
Short primer in atmospheric physics
The atmosphere is made up of the troposphere, stratosphere, mesosphere, thermosphere, exosphere and at the top the ionosphere. (Technically the ionosphere is part of the thermosphere.)The ionosphere is made up of ionized radiation. This is from the sun's solar winds, and this all gets trapped in the ionosphere in a near plasma state. The ionosphere is home to the aurora lights, and is also an excellent reflector of radio waves. The ionosphere can be used as a medium for long distance communication. HAARP's goal is to enhance communication technologies and radar capabilities. For example, they have devised a way to track submarines deep underwater using ELF waves. ELF waves are extremely low frequency waves which because of their low frequency can pass through sea water with ease. Here are some scientific journals published from HAARP that fully explain the work they are doing. (2)(3)(4)
Nichola Tesla invented an earthquake machine
Nichola Tesla was a technological genius. He developed ways to make wireless electricity, wireless communication (radio) and patented over 200 inventions. While living in New York, he developed a 7 inch long 2 poung mechanical ossilator. It is claimed that one day while testing it out, it caused an earthquake.
""I was experimenting with vibrations. I had one of my machines going and I wanted to see if I could get it tune with the vibration of the building. I put it up notch after notch. Suddenly, all the heavy machinery in the place was flying around. I grabbed a hammer and broke the machine. Outside in the street there was pandemonium. The police and ambulance arrived. We told the police it must have been an earthquake. I told my assistants to say nothing.""
I'm a little skeptical that something that small and simple could shake buildings. Has anyone replicated Tesla's findings since then? The only other test of this device I'm aware of was done by the Mythbuster's crew, and they failed to replicate the effect. Seems a bit strange that after 110 years, no one else has made one in their basements and come forward. 
HAARP alters the weather
According to HAARP's official website:
"The HAARP facility will not affect the weather. Transmitted energy in the frequency ranges that will be used by HAARP is not absorbed in either the troposphere or the stratosphere - the two levels of the atmosphere that produce the earth's weather. Electromagnetic interactions only occur in the near-vacuum of the rarefied region above about 70 km known as the ionosphere."
This is a major misunderstanding about HAARP. It's research is no where near the troposphere or stratosphere, which it would be required to affect the weather. The sun gives off a million times the energy HAARP all of the time, and yet we don't see sporadic storms. The total amount of radiated output energy HAARP gives off is 3,600 kilowatts. This is the same amount of output energy that a large AM radio station gives off! A lot of the HAARP CT's seem to confuse the required amount of power for the antennas with the energy the antennas can give off. The power required for the antennas are around 3 million watts, but again this power can not be used to create death rays or hurricanes.
There is a patent for weather modification technology. This was later turned into HAARP.
"A method and apparatus for altering at least one selected region which normally exists above the earth's surface. The region is excited by electron cyclotron resonance heating to thereby increase its charged particle density. In one embodiment, circularly polarized electromagnetic radiation is transmitted upward in a direction substantially parallel to and along a field line which extends through the region of plasma to be altered. The radiation is transmitted at a frequency which excites electron cyclotron resonance to heat and accelerate the charged particles. This increase in energy can cause ionization of neutral particles which are then absorbed as part of the region thereby increasing the charged particle density of the region."
This was patented by Bernard Eastlund in the 1980's. Just because something is patented, it doesn't mean that its already been built or even that the thing will work. One of the problems with this and many other patents brought up on conspiracy sites, is that the amount of power needed to create hurricanes is no where near the energy HAARP is able to produce. Bernard Eastlund has said this from the beginning.
"One of the reasons weather modification is not a science is that scientists have made what they considered to be reasonable assessments of the relative size of forcing technologies (such as wind generators, microwave heaters, or explosions) and determined that the large size of
weather systems make it useless to attempt to change weather patterns with human intervention.
The energy turnover of a storm system can be related to an equivalent power through the rainfall rate. The various severe storm categories are related to the total electric power consumption of New York City in the table below:
SMALL THUNDERSTORM 10 New York Cities
LARGE THUNDERSTORM 1000 New York Cities
MAJOR STORM SYSTEM 10000 New York Cities
HURRICANE 100,000 New York Cities
The power levels required for the ARCO antenna to create MEV electrons and defeat a missile attack by the Soviet Union was estimated to require generation of a power equivalent to 100,000 New York Cities for a time period of 20 minutes." 
In 2005, Bernard Eastlund had this to say about the current state of weather modification technology:
"I estimate this new science of weather modification will take 10 to 20 years to mature to the point where it is useful for controlling the severity and impact of severe weather systems as large as hurricanes,"
In 1977 the UN passed a resolution to ban weather modification technology
This is often brought up as proof that the technology already existed. Why would they ban something that didn't even exist? The reason the UN passed this resolution was because at the time, the US had been working on a weather modification project called Project Popeye, which involved cloud seeding.
"Its goal was to prolong the monsoon season and thus impede the movement of enemy troops and supplies on muddy jungle trails." 
This resolution only banned weather modification when used as a weapon. This would not ban technologies that redirect hurricanes or prevent tornadoes from forming. Both of those are current goals, that have not yet been met. If we can't even swerve hurricanes, how could we create them? Oh that's right. Every country is keeping this a secret, because technology like this isn't important, interesting or beneficial.
Cloud seeding has been around for 100 years. You don't think hurricane seeding has been invented yet?
At the moment, cloud seeding has not yet been proven to work. There are a lot of skeptical scientists who think that cloud seeding has very little impact on the rain at all. The technology has been around for a while, but there hasn't been much progress despite the millions of dollars of research grants over the past 50 years. China claims to have successfully used in for the 2008 Olympics, but in reality they only seemingly managed to prevent rain on the opening day. This involved shooting 1104 dispersal rockets into the atmosphere from 21 locations around the city. For more on how cloud seeding works, check out http://science.howstuffworks.com/cloud-seeding1.htm
"I'm very skeptical about what they claim they can do," said Roelof Bruintjes, the lead researcher for U.S. National Center for Atmospheric Research in Boulder, Colorado in 2008.
In 2003, the United States National Academy of Sciences declared that their 30 years of weather modification studies had not produced convincing evidence that weather modification works. 
HAARP's ELF waves can be used for mind control purposes
Three questions and answers displayed on HAARP's FAQ page, should give you an idea on how implausible this claim is.
"Can HAARP be used to generate ELF?
Yes. However, the HAARP facility does not directly transmit signals in the ELF frequency range. Instead, ELF signals are generated in the ionosphere at an altitude of around 100 km. Frequencies ranging from below one Hz to about 20 kHz can be generated through this ionospheric interaction process.
How strong are the ELF signals generated using HAARP?
Under optimum conditions, signals generated using ionospheric interaction techniques may be measured in the tens of pT range and tend to be strongest at frequencies around 2 kHz.
Is there any safety concern with the ELF signals generated using HAARP?
No. These signals are more than eleven million times weaker (smaller) than the Earth's background field and about one million times weaker (smaller) than the level where researchers have reported biological effects in the literature. Signals generated through ionospheric interaction are so weak, in fact, that sophisticated instruments must be used to observe them. Nevertheless, they are still valuable for scientific purposes and for communication applications."
The whole concept of a government using 'mind control" technology lacks any grounding in common sense and logic. Why would the government need to use mind control for entire populations? Are we that out of control? And how would this so called technology work? Does it alter our moods, or is this going to work like some kind of Jedi mind trick? The conspiracy theorists are prettty much implying that our own government and military are just as paranoid as themselves. No wonder they can't make sense of reality.
In 2008, strange lights have been recorded right before the earthquake in China
Of course this claim implies that HAARP was behind it. There is a connection with HAARP and aurora lights, but if HAARP was using its so-called "earthquake" mode, why would we see a aurora, more importantly why would we see it in China? Wouldn't we see it in Alaska? Apparently earthquake lights is not a new phenomenon. It wasn't until
the Matsushiro earthquake swarm in Japan between 1965 and 1967 that the scientific community acknowledged its existence. (1) These lights have an unknown mechanism, but discovering what causes them may lead to forecasting earthquakes hours beforehand.
Former Secretery of Defense William Cohen admits earthquake technology exists
This claim sounds convincing when you read the passage provided on CT sites. But as predicted this is another case of quote-mining.
"The same thing is true about just the false scare of a threat of using some kind of a chemical weapon or a biological one. There are some reports, for example, that some countries have been trying to construct something like an Ebola Virus, and that would be a very dangerous phenomenon, to say the least. Alvin Toeffler has written about this in terms of some scientists in their laboratories trying to devise certain types of pathogens that would be ethnic specific so that they could just eliminate certain ethnic groups and races; and others are designing some sort of engineering, some sort of insects that can destroy specific crops. Others are engaging even in an eco- type of terrorism whereby they can alter the climate, set off earthquakes, volcanoes remotely through the use of electromagnetic waves.
So there are plenty of ingenious minds out there that are at work finding ways in which they can wreak terror upon other nations. It's real, and that's the reason why we have to intensify our efforts, and that's why this is so important." 
It helps out a lot in understanding the quote when you know who Alvin Toeffler is. He is a futurist author who has written books on future military and political possibilities. William Cohen assures us that this is real, but what he is referring to is the ingenious minds at work, who are possibly trying to create the things he described. But again, there is no conclusive evidence that any of these nations have been working on such technologies or that they possess them.
Hugo Chavez claims that the United States used an "earthquake weapon" on Haiti
HAARP deleted its records on the day of the 2010 earthquake
Sadly, an article was dedicated to this claim. The "researcher" accidentally put in the wrong year when he tried this out on HAARP's website. He put 2001 instead of 2010! Not only that but he got the day wrong as well. He seems to have missed proofreading, as 2001 is right in the article.
"Set the date in "Chart Archives" below the today's graph to 2001/Jan/
11 in the window below the graph and see for your selves. It is the only
instance of such an occurrence I have discovered by looking through
other historical dates.
HAARP caused Hurricane Katrina