# Trump On North Korea: ‘Rocket Man Is On A Suicide Mission’

President Donald Trump‘s first address to the United Nations General Assembly was marked by tough talk for North Korea and Iran.

The president referred to North Korean leader Kim Jong Un as “rocket man” and threatened to “totally destroy North Korea” if the United States is forced to defend itself or allies against the North’s aggression.

“The United States has great strength and patience, but if it is forced to defend itself or its allies, we will have no choice but to totally destroy North Korea,” Trump said Tuesday. “Rocket Man is on a suicide mission for himself and for his regime. The United States is ready, willing, and able, but hopefully this will not be necessary.”

The UN secretary general warned UN members Tuesday morning that the threat of a nuclear attack is at its highest level since the end of the Cold War, and that fiery talk can lead to fatal misunderstandings, CBS2’s Alice Gainer reported.

At the Pentagon, U.S. Secretary of Defense Jim Mattis was asked about the president’s new nickname for Kim Jong Un.

“We’re dealing with the North Korea situation through the international processes, and we will continue to do so with Secretary Tillerson leading the effort,” he said. “We will hopefully get this resolved through diplomatic means.”

Trump also slammed the Iranian government, calling it an “economically depleted rogue state” whose chief export is violence.

Questioning the 2015 nuclear deal with Iran, Trump said the world cannot allow the “murderous regime” to continue its destabilizing activities while building dangerous missiles. He added world leaders “cannot abide” by the agreement if it “provides cover” for Iran to eventually build its nuclear program.

“The Iran deal was one of the worst and most one-sided transactions the United States has ever entered into. Frankly, that deal is an embarrassment to the United States, and I don’t think you’ve heard the last of it, believe me. It is time for the entire world to join us in demanding that Iran’s government end its pursuit of death and destruction,” Trump said.

French President Emmanuel Macron said that scrapping the deal would be a big mistake.

“I think that it’s better than nothing,” he said.

Iran’s president hasn’t given any specifics about how the country would react to a withdrawal.

“Given that Mr. Trump’s reactions and actions and policies are somewhat unpredictable, we have had long thought and discussions about our reactions,” President Hassan Rouhani said.

During his more than 40-minute inaugural address to the UN General Assembly, Trump said that he will “always put America first” and the U.S. can no longer be taken advantage of in its dealings around the globe.

Trump said he will “defend America’s interests above all else.” He says the U.S. will “forever be a great friend to the world,” including its allies, but the U.S. can no longer be taken advantage of and get nothing in return.

But Trump said that UN member states should unite to face global dangers, and rallied other countries to do their part in solving global issues, including sharing the burden of fighting terrorism.

“We live in a time of extraordinary opportunity… but each day also brings news of growing dangers that threaten everything we cherish and value,” Trump said. “Terrorists and extremists have gathered strength and spread to every region of the planet. Rogue regimes represented in this body not only support terrorists but threaten other nations and their own people with the most destructive weapons known to humanity.”

“To put it simply, we meet at a time of both immense promise and great peril,” Trump said. “It is entirely up to us whether we lift the world to new heights or let it fall into a valley of disrepair.”

The president talked tough on terror saying “it is time to expose and hold responsible” nations that provide funding and safe harbor to terror groups. He says all responsible nations must work together to confront terrorists and “the Islamic extremist that inspires them.”

“We will stop radical Islamic terrorism, because we cannot allow it to tear up our nation and, indeed, to tear up the entire world,” said the president.

The leaders of Russia and China, among others, were not in attendance. Trump did not mention Russia in his speech, but he will meet with Russia’s foreign minister and host a reception for UN leaders Tuesday night.

After his address, Trump went to a luncheon where he gave a toast, admittedly calling himself a critic of the UN for years.

“To the potential — the great, great potential — of the United Nations. Thank you all for being here,” he said.

More: UN General Assembly Street Closures

In his first appearance at the United Nations on Monday, Trump made a call for sweeping reforms.

“In recent years, the United Nations has not reached its full potential because of bureaucracy and mismanagement,” Trump said.

The U.S. is the UN’s largest contributor, paying at least 25 percent of the operating budget. The president encouraged other nations to consider joining in, reviewing the UN’s spending and efficiency.

“I think the main message is ‘Make the United Nations great,’ not again, ‘Make the United Nations great.’ Such tremendous potential and I think we’ll be able to do this,” Trump said.

“Major portions of the world are in conflict and some in fact are going to hell, but the powerful people in this room, under the guidance and auspices of the United Nations can solve many of these vicious and complex problems,” Trump said. “The American people hope that one day soon the United Nations can be a much more accountable and effective advocate for human dignity and freedom around the world.”

North Korea was a major conversation point in Monday’s phone call with China’s president. Trump also met with French President Emanuel Macron and Israeli Prime Minister Benjamin Netanyahu focused on Iran.

Dinner with Latin American leaders was centered around trade and instability in Venezuela, which Trump addressed during his speech Tuesday.

“The Venezuelan people are starving, and their country is collapsing, their Democratic institutions are being destroyed,” Trump said. “This situation is completely unacceptable and we cannot stand by and watch. As a responsible neighbor and friend, we and all others have a goal — that goal is to help them regain their freedom, recover their country and restore their democracy.”

Trump accused its President Nicolas Maduro of stealing power from elected representatives to preserve his “disastrous rule.”

There is no sign that Trump will falter on his choice to withdraw from the Paris Climate Accord unless it is renegotiated, which will likely be a major topic this week.

Trump On North Korea: ‘Rocket Man Is On A Suicide Mission’

# Mexico City hit by deadly 7.1 magnitude earthquake on anniversary of 1985 disaster

Rescuers search through rubble after the city is struck on the anniversary of a 1985 quake that killed thousands of people.

A major earthquake has struck central Mexico, with reports that at least 134 people have been killed and thousands forced on to the streets.

Panicked workers fled from office buildings and clouds of dust rose up from the crumbling facades of damaged buildings after the 7.1 magnitude quake struck.

The tremors came hours after preparation drills were held on the anniversary of a devastating 1985 earthquake that killed more than 5,000 people in the city.

At least 30 people had died in the capital, while there were reports of people trapped in collapsed and burning buildings and local TV footage showed rescuers frantically trying to dig into rubble with pickaxes.

Speaking minutes after the earthquake struck, resident Georgina Sanchez sobbed: “I’m so worried. I can’t stop crying. It’s the same nightmare as in 1985.”

https://www.instagram.com/p/BZO_UM9lvbH/embed/?cr=1&v=7&wp=538#%7B%22ci%22%3A0%2C%22os%22%3A314.25000000000006%7D

Gala Dluzhynska said she was taking a class with 11 other women on the second floor of a building in the fashionable Alvaro Obregon street area when window and ceiling panels fell as the building began to tear apart.

She said she fell in the stairs and people began to walk over her, before someone finally pulled her up.

“There were no stairs anymore. There were rocks,” she said.

The US Geological Survey said the quake was centred near Raboso in Puebla state, 76 miles (123km) southeast of Mexico City.

A civil protection official in Puebla said two people had been killed after a school collapsed, while Mexico state’s governor confirmed eight deaths, including a quarry worker killed by a rockslide and another victim hit by a falling lamppost.

Officials asked people not to smoke in the streets of Mexico City – which has a population of 20 million – warning of possible ruptured gas pipes.

God bless the people of Mexico City. We are with you and will be there for you.

Mexico City International Airport suspended operations, while electricity and phone lines were down in parts of the capital.

“We got out really fast, leaving everything as it was and just left,” said Rosaura Suarez, as she stood with a crowd on the street.

Alfredo Aguilar, 43, said the quake was “really strong – buildings started to move”.

He added that he saw a woman fainting as “people started to run.”

The earthquake came less than two weeks after an 8.1 magnitude tremor in southern Mexico killed at least 98 people.

Mexico’s President Enrique Pena Nieto was on a flight to Oaxaca – one of the areas hardest hit by the previous quake – on Tuesday.

He tweeted that he would be returning to Mexico City as soon as possible to deal with the emergency.

http://news.sky.com/story/mexico-city-hit-by-71-magnitude-earthquake-on-anniversary-of-1985-disaster-11043859

# At least five dead’ after 7.1-magnitude earthquake rocks Mexico City – shaking buildings and sending people fleeing into the street

• Tremor hit hours after emergency drills around the nation on the anniversary of another devastating quake
• Horrifying images coming out of country’s capital show rubble and chunks of buildings strewn across roads
• Local resident Georgina Sanchez said: ‘I’m so worried. I can’t stop crying. It’s the same nightmare as in 1985’

At least five people are dead after a 7.1-magnitude earthquake hit Mexico leaving buildings shaking and sending people fleeing into the street.

The tremor hit just hours after emergency drills around the nation on the anniversary of another devastating quake that killed thousands in Mexico City in 1985.

Today’s quake hit 5 miles southeast of Atencingo in the central state of Puebla at a depth of 32 miles, the US Geological Survey said.

Horrifying images coming out of the country’s capital show rubble strewn across roads and enormous chunks of collapsed buildings laying on the ground with hundreds of terrified locals fleeing onto the streets.

As structures fell around her, local resident Georgina Sanchez, 52, said: ‘I’m so worried. I can’t stop crying. It’s the same nightmare as in 1985.’

It comes just days after a powerful 8.1 quake hit Mexico killing at least 98 people.

At least five people are dead after a 7.1-magnitude earthquake hit Mexico leaving buildings shaking and sending people fleeing into the street.

The tremor hit just hours after emergency drills around the nation on the anniversary of another devastating quake that killed thousands in Mexico City in 1985.

Today’s quake hit 5 miles southeast of Atencingo in the central state of Puebla at a depth of 32 miles, the US Geological Survey said.

Horrifying images coming out of the country’s capital show rubble strewn across roads and enormous chunks of collapsed buildings laying on the ground with hundreds of terrified locals fleeing onto the streets.

As structures fell around her, local resident Georgina Sanchez, 52, said: ‘I’m so worried. I can’t stop crying. It’s the same nightmare as in 1985.’

It comes just days after a powerful 8.1 quake hit Mexico killing at least 98 people.

Rescuers are seen working through piles of debris in Mexico City with the help of bystanders

In the capital Mexico City, thousands of people streamed out of buildings into the streets in a panic filling the plaza around the Independence Monument with a mass of people.

Traffic came to a standstill as masses of workers blocked streets while clouds of dust rose from fallen facades.

Office workers were also seen hugging each other to calm themselves.

In the city’s Roma neighborhood small piles of stucco and brick fallen from building facades littered the streets.

Panic in Mexico City as 7.1 earthquake hits capital

Two men calmed a woman, blood trickling form a small wound on her knee, seated on a stool in the street, telling her to breathe deeply.

Lazaro Frutis, a 45-year-old who escaped an office building before it crumpled to the ground, said: ‘We ran outside thinking all was going to collapse around us.

‘The worst thing is, we don’t know about our families or anything.’

At a nearby market, a worker in a hard hat walked around the outside of the building, warning people not to smoke as a smell of cooking gas filled the air.

The earthquake struck 5 miles southeast of Atencingo in the central state of Puebla at a depth of 32 miles

It comes just days after a powerful 8.1 quake hit Mexico killing at least 98 people. Locals are pictured helping a woman during today’s incident

Office workers huddle as major earthquake shakes Mexico City

Market stall vendor Edith Lopez, 25, was caught up in the quake and said she saw glass bursting out of the windows of some buildings.

Mexico City’s international airport suspended operations with personnel checking the structures for damage. It is not immediately clear how many flights have been affected.

Earlier this month, an 8.1 magnitude quake struck off the coast of Chiapas killing at least 98 people.

Streams of smoke were seen streaming from piles of collapsed buildings in the capital Mexico City

Mexicans were left shocked as the quake struck just hours after emergency drills

The hardest-hit area was Juchitan, Oaxaca, where a third of the city’s homes collapsed or were uninhabitable.

The remains of brick walls and clay tile roofs cluttered streets as families dragged mattresses on to pavements to spend another anxious night sleeping outdoors.

Members of the ‘Topos’ (Moles) specialised rescue team dug through piles of debris looking for folk’s loved ones and hoping to find some that were still alive.

People fled for their lives after the earthquake struck the capital Mexico City

Today’s quake hit 5 miles southeast of Atencingo in the central state of Puebla at a depth of 32 miles, the US Geological Survey said

Soldiers of the Army and Navy also joined in on the search and rescue, hoping to locate the bodies still missing in the wreckage.

Pena Nieto declared three days of national mourning when he first broke numbers on the deaths associated with the earthquake

The epicenter of the earthquake was 123km southwest of the town of Pijijiapan.

# Mexico City airport suspends operations following 7.1 magnitude earthquake

By Associated Press |

MEXICO CITY (AP) – The Latest on the strong earthquake that hit Mexico City (all times local):

2:55 a.m.

Mexico City’s international airport says it has suspended operations due to the magnitude 7.1 quake that shook the central part of the country.

The airport says in a tweet that airport personnel are checking the structures for damage. It’s not immediately clear how many flights have been affected.

The U.S. Geological Survey said the quake was centered near the Puebla state town of Raboso, about 76 miles (123 kilometers) southeast of Mexico City.

___

2:45 p.m.

Mexican television stations are showing dramatic images a several story building collapsing following a magnitude 7.1 earthquake that rattled the center of the country. It was unclear if people were inside the building.

Numerous other buildings collapsed or suffered serious damage across central Mexico in Tuesday’s quake.

The U.S. Geological Survey said the quake had a magnitude of 7.1 and was centered near the Puebla state town of Raboso, about 76 miles (123 kilometers) southeast of Mexico City.

2:20 p.m.

Mexican television stations are broadcasting images of collapsed buildings in heavily populated parts of the city following Tuesday’s magnitude 7.1 earthquake. Televisa broadcast images of a plume of smoke rising from one large structure.

One of the collapsed buildings is a large parking garage alongside a hospital.

There are no immediate reports on casualties.

___

2:10 p.m.

Puebla Gov. Tony Gali says buildings have been damaged in his state in central Mexico by a magnitude 7.1 earthquake.

Gali said on his official Twitter account that “we will continue reviewing” damages and urged people to follow emergency procedures.

“What we have reports of is material damage … we have no reports of deaths so far,” tweeted Puebla Interior Secretary Diodoro Carrasco.

He said the towers of some churches have fallen in the city of Cholula, which is famous for its many churches.

The U.S. Geological Survey said the quake had a magnitude of 7.1 and was centered near the Puebla state town of Raboso, about 76 miles (123 kilometers) southeast of Mexico City.

___

2 p.m.

On Mexico City’s main boulevard, thousands of people streamed out of buildings into the streets in a panic, filling the plaza around the Independence Monument with a mass of people.

Office workers hugged each other to calm themselves.

In the city’s Roma neighborhood, which was struck hard by the 85 quake, small piles of stucco and brick fallen from building facades littered the streets.

Two men calmed a woman, blood trickling form a small wound on her knee, seated on a stool in the street, telling her to breathe deeply.

At a nearby market, a worker in a hard hat walked around the outside of the building, warning people not to smoke as a smell of cooking gas filled the air.

Market stall vendor Edith Lopez, 25, had been in a taxi a few blocks away when the quake struck. She said she saw glass bursting out of the windows of some buildings.

1:50 p.m.

Buildings have been seriously damaged in Mexico City after a 7.1 magnitude earthquake shook central Mexico.

Local television stations broadcast images of collapsed facades and streets filled with rubble.

There were no immediate reports of casualties.

___

1:35 p.m.

The U.S. Geological Survey says it calculates the earthquake that struck central Mexico as magnitude 7.1

It says the epicenter was near the town of Raboso, about 76 miles (123 kilometers) southeast of Mexico City.

Mexico’s seismological agency calculated its preliminary magnitude at 6.8 and said its center was east of the city in the state of Puebla.

Earlier in the day buildings across the city held preparation drills on the anniversary of the 1985 quake.

http://www.ktuu.com/content/news/UPDATE-Buildings-collapse-following-71-magnitude-earthquake-in-Mexico-445804783.html

# Richter magnitude scale

The Richter magnitude scale (ML, also Richter scale) assigns a magnitude number to quantify the size of an earthquake. The Richter scale, developed in the 1930s, is a base-10logarithmic scale, which defines magnitude as the logarithm of the ratio of the amplitude of the seismic waves to an arbitrary, minor amplitude, as recorded on a standardized seismograph at a standard distance.

As measured with a seismometer, an earthquake that registers 5.0 on the Richter scale has a shaking amplitude 10 times greater than an earthquake that registered 4.0 at the same distance. As energy release is generally proportional to the shaking amplitude raised to the 32 power, an increase of 1 magnitude corresponds to a release of energy 31.6 times that released by the lesser earthquake.[1] This means that, for instance, an earthquake of magnitude 5 releases 31.6 times as much energy as an earthquake of magnitude 4.

The Richter scale built on the previous, more subjective Mercalli intensity scale by offering a quantifiable measure of an earthquake’s size.[2]

In the United States, the Richter scale was succeeded in the 1970s by the moment magnitude scale. The moment magnitude is currently used by the US Geological Survey to describe magnitudes for all earthquakes.[3]

## Development

In 1935, seismologistsCharles Francis Richter and Beno Gutenberg of the California Institute of Technology developed a scale, later dubbed the Richter magnitude scale, for computing the magnitude of earthquakes, specifically those recorded and measured with the Wood-Anderson torsion seismograph in a particular area of California. Originally, Richter reported mathematical values to the nearest quarter of a unit, but the values later were reported with one decimal place; the local magnitude scale compared the magnitudes of different earthquakes.[1] Richter derived his earthquake-magnitude scale from the apparent magnitude scale used to measure the brightness of stars.[4]

Richter established a magnitude 0 event to be an earthquake that would show a maximum, combined horizontal displacement of 1.0 µm (3.9×10−5 in) on a seismogram recorded with a Wood-Anderson torsion seismograph 100 km (62 mi) from the earthquake epicenter. That fixed measure was chosen to avoid negative values for magnitude, given that the slightest earthquakes that could be recorded and located at the time were around magnitude 3.0. The Richter magnitude scale itself has no lower limit, and contemporary seismometers can register, record, and measure earthquakes with negative magnitudes.

{\displaystyle M_{\text{L}}} (local magnitude) was not designed to be applied to data with distances to the hypocenter of the earthquake that were greater than 600 km (370 mi).[3] For national and local seismological observatories, the standard magnitude scale in the 21st century is still {\displaystyle M_{\text{L}}}. However, this scale cannot measure magnitudes above about {\displaystyle M_{\text{L}}} = 7,[5] because the high frequency waves recorded locally have wavelengths shorter than the rupture lengths[clarification needed] of large earthquakes.

Later, to express the size of earthquakes around the planet, Gutenberg and Richter developed a surface wave magnitude scale ({\displaystyle M_{\text{s}}}) and a body wave magnitude scale ({\displaystyle M_{\text{b}}}).[6] These are types of waves that are recorded at teleseismicdistances. The two scales were adjusted such that they were consistent with the {\displaystyle M_{\text{L}}} scale. That adjustment succeeded better with the {\displaystyle M_{\text{s}}} scale than with the {\displaystyle M_{\text{b}}} scale. Each scale saturates when the earthquake is greater than magnitude 8.0.

Because of this, researchers in the 1970s developed the moment magnitude scale ({\displaystyle M_{\text{w}}}). The older magnitude-scales were superseded by methods for calculating the seismic moment, from which was derived the moment magnitude scale.

About the origins of the Richter magnitude scale, C.F. Richter said:

I found a [1928] paper by Professor K. Wadati of Japan in which he compared large earthquakes by plotting the maximum ground motion against [the] distance to the epicenter. I tried a similar procedure for our stations, but the range between the largest and smallest magnitudes seemed unmanageably large. Dr. Beno Gutenberg then made the natural suggestion to plot the amplitudes logarithmically. I was lucky, because logarithmic plots are a device of the devil.

## Details

The Richter scale was defined in 1935 for particular circumstances and instruments; the particular circumstances refer to it being defined for Southern California and “implicitly incorporates the attenuative properties of Southern California crust and mantle.”[7] The particular instrument used would become saturated by strong earthquakes and unable to record high values. The scale was replaced in the 1970s by the moment magnitude scale (MMS, symbol Mw); for earthquakes adequately measured by the Richter scale, numerical values are approximately the same. Although values measured for earthquakes now are {\displaystyle M_{w}} (MMS), they are frequently reported by the press as Richter values, even for earthquakes of magnitude over 8, when the Richter scale becomes meaningless. Anything above 5 is classified as a risk by the USGS.[citation needed]

The Richter and MMS scales measure the energy released by an earthquake; another scale, the Mercalli intensity scale, classifies earthquakes by their effects, from detectable by instruments but not noticeable, to catastrophic. The energy and effects are not necessarily strongly correlated; a shallow earthquake in a populated area with soil of certain types can be far more intense in effects than a much more energetic deep earthquake in an isolated area.

Several scales have historically been described as the “Richter scale”, especially the local magnitude{\displaystyle M_{\text{L}}} and the surface wave {\displaystyle M_{\text{s}}} scale. In addition, the body wave magnitude{\displaystyle m_{\text{b}}}, and the moment magnitude{\displaystyle M_{\text{w}}}, abbreviated MMS, have been widely used for decades. A couple of new techniques to measure magnitude are in the development stage by seismologists.

All magnitude scales have been designed to give numerically similar results. This goal has been achieved well for {\displaystyle M_{\text{L}}}{\displaystyle M_{\text{s}}}, and {\displaystyle M_{\text{w}}}.[2][8] The {\displaystyle m_{\text{b}}} scale gives somewhat different values than the other scales. The reason for so many different ways to measure the same thing is that at different distances, for different hypocentral depths, and for different earthquake sizes, the amplitudes of different types of elastic waves must be measured.

{\displaystyle M_{\text{L}}} is the scale used for the majority of earthquakes reported (tens of thousands) by local and regional seismological observatories. For large earthquakes worldwide, the moment magnitude scale (MMS) is most common, although {\displaystyle M_{\text{s}}} is also reported frequently.

The seismic moment{\displaystyle M_{o}}, is proportional to the area of the rupture times the average slip that took place in the earthquake, thus it measures the physical size of the event. {\displaystyle M_{\text{w}}} is derived from it empirically as a quantity without units, just a number designed to conform to the {\displaystyle M_{\text{s}}} scale.[9] A spectral analysis is required to obtain {\displaystyle M_{o}}, whereas the other magnitudes are derived from a simple measurement of the amplitude of a specifically defined wave.

All scales, except {\displaystyle M_{\text{w}}}, saturate for large earthquakes, meaning they are based on the amplitudes of waves which have a wavelength shorter than the rupture length of the earthquakes. These short waves (high frequency waves) are too short a yardstick to measure the extent of the event. The resulting effective upper limit of measurement for {\displaystyle M_{L}} is about 7[5] and about 8.5[5] for {\displaystyle M_{\text{s}}}.[10]

New techniques to avoid the saturation problem and to measure magnitudes rapidly for very large earthquakes are being developed. One of these is based on the long period P-wave;[11] the other is based on a recently discovered channel wave.[12]

The energy release of an earthquake,[13] which closely correlates to its destructive power, scales with the 32 power of the shaking amplitude. Thus, a difference in magnitude of 1.0 is equivalent to a factor of 31.6 ({\displaystyle =({10^{1.0}})^{(3/2)}}) in the energy released; a difference in magnitude of 2.0 is equivalent to a factor of 1000 ({\displaystyle =({10^{2.0}})^{(3/2)}}) in the energy released.[14] The elastic energy radiated is best derived from an integration of the radiated spectrum, but an estimate can be based on {\displaystyle m_{\text{b}}} because most energy is carried by the high frequency waves.

## Richter magnitudes

The Richter magnitude of an earthquake is determined from the logarithm of the amplitude of waves recorded by seismographs (adjustments are included to compensate for the variation in the distance between the various seismographs and the epicenter of the earthquake). The original formula is:[15]

{\displaystyle M_{\mathrm {L} }=\log _{10}A-\log _{10}A_{\mathrm {0} }(\delta )=\log _{10}[A/A_{\mathrm {0} }(\delta )],\ }

where A is the maximum excursion of the Wood-Anderson seismograph, the empirical function A0 depends only on the epicentral distance of the station, {\displaystyle \delta }. In practice, readings from all observing stations are averaged after adjustment with station-specific corrections to obtain the {\displaystyle M_{\text{L}}} value.

Because of the logarithmic basis of the scale, each whole number increase in magnitude represents a tenfold increase in measured amplitude; in terms of energy, each whole number increase corresponds to an increase of about 31.6 times the amount of energy released, and each increase of 0.2 corresponds to a doubling of the energy released.

Events with magnitudes greater than 4.5 are strong enough to be recorded by a seismograph anywhere in the world, so long as its sensors are not located in the earthquake’s shadow.

The following describes the typical effects of earthquakes of various magnitudes near the epicenter. The values are typical only. They should be taken with extreme caution, since intensity and thus ground effects depend not only on the magnitude, but also on the distance to the epicenter, the depth of the earthquake’s focus beneath the epicenter, the location of the epicenter and geological conditions (certain terrains can amplify seismic signals).

Magnitude Description Mercalli intensity Average earthquake effects Average frequency of occurrence (estimated)
1.0–1.9 Micro I Microearthquakes, not felt, or felt rarely. Recorded by seismographs.[16] Continual/several million per year
2.0–2.9 Minor I to II Felt slightly by some people. No damage to buildings. Over one million per year
3.0–3.9 III to IV Often felt by people, but very rarely causes damage. Shaking of indoor objects can be noticeable. Over 100,000 per year
4.0–4.9 Light IV to VI Noticeable shaking of indoor objects and rattling noises. Felt by most people in the affected area. Slightly felt outside. Generally causes none to minimal damage. Moderate to significant damage very unlikely. Some objects may fall off shelves or be knocked over. 10,000 to 15,000 per year
5.0–5.9 Moderate VI to VII Can cause damage of varying severity to poorly constructed buildings. At most, none to slight damage to all other buildings. Felt by everyone. 1,000 to 1,500 per year
6.0–6.9 Strong VIII to X Damage to a moderate number of well-built structures in populated areas. Earthquake-resistant structures survive with slight to moderate damage. Poorly designed structures receive moderate to severe damage. Felt in wider areas; up to hundreds of miles/kilometers from the epicenter. Strong to violent shaking in epicentral area. 100 to 150 per year
7.0–7.9 Major X or greater[17] Causes damage to most buildings, some to partially or completely collapse or receive severe damage. Well-designed structures are likely to receive damage. Felt across great distances with major damage mostly limited to 250 km from epicenter. 10 to 20 per year
8.0–8.9 Great Major damage to buildings, structures likely to be destroyed. Will cause moderate to heavy damage to sturdy or earthquake-resistant buildings. Damaging in large areas. Felt in extremely large regions. One per year
9.0 and greater At or near total destruction – severe damage or collapse to all buildings. Heavy damage and shaking extends to distant locations. Permanent changes in ground topography. One per 10 to 50 years

(Based on U.S. Geological Survey documents.)[18]

The intensity and death toll depend on several factors (earthquake depth, epicenter location, population density, to name a few) and can vary widely.

Minor earthquakes occur every day and hour. On the other hand, great earthquakes occur once a year, on average. The largest recorded earthquake was the Great Chilean earthquake of May 22, 1960, which had a magnitude of 9.5 on the moment magnitude scale.[19]The larger the magnitude, the less frequently the earthquake happens.

Beyond 9.5, while extremely strong earthquakes are theoretically possible, the energies involved rapidly make such earthquakes on Earth effectively impossible without an extremely destructive source of external energy. For example, the asteroid impact that created the Chicxulub crater and caused the mass extinction that may have killed the dinosaurs has been estimated as causing a magnitude 13 earthquake (see below), while a magnitude 15 earthquake could destroy the Earth completely.[citation needed] Seismologist Susan Hough has suggested that 10 may represent a very approximate upper limit, as the effect if the largest known continuous belt of faults ruptured together (along the Pacific coast of the Americas).[20]

### Energy release equivalents

The following table lists the approximate energy equivalents in terms of TNT explosive force – though note that the earthquake energy is released underground rather than overground.[21] Most energy from an earthquake is not transmitted to and through the surface; instead, it dissipates into the crust and other subsurface structures. In contrast, a small atomic bomb blast (see nuclear weapon yield) will cause only light shaking of indoor items, since its energy is released above ground.

Approximate magnitude Approximate TNT equivalent for
seismic energy yield
Joule equivalent Example
0.0 15 g 63 kJ
0.2 30 g 130 kJ Large hand grenade
1.5 2.7 kg 11 MJ Seismic impact of typical small construction blast
2.1 21 kg 89 MJ West fertilizer plant explosion[22]
3.0 480 kg 2.0 GJ Oklahoma City bombing, 1995
3.5 2.7 metric tons 11 GJ PEPCON fuel plant explosion, Henderson, Nevada, 1988
3.87 9.5 metric tons 40 GJ Explosion at Chernobyl nuclear power plant, 1986
3.91 11 metric tons 46 GJ Massive Ordnance Air Blast bomb
6.0 15 kilotons 63 TJ Approximate yield of the Little Boy atomic bomb dropped on Hiroshima (~16 kt)
7.9 10.7 megatons 45 PJ Tunguska event
8.35 50 megatons 210 PJ Tsar Bomba—Largest thermonuclear weapon ever tested. Most of the energy was dissipated in the atmosphere. The seismic shock was estimated at 5.0–5.2[23]
9.15 800 megatons 3.3 EJ Toba eruption 75,000 years ago; among the largest known volcanic events.[24]
13.0 100 teratons 420 ZJ Yucatán Peninsula impact (creating Chicxulub crater) 65 Ma ago (108 megatons; over 4×1029 ergs = 400 ZJ).[25][26][27][28][29]

## Magnitude empirical formulae

These formulae for Richter magnitude {\displaystyle \textstyle M_{\mathrm {L} }} are alternatives to using Richter correlation tables based on Richter standard seismic event ({\displaystyle M_{\mathrm {L} }}=0, A=0.001mm, D=100 km). Below, {\displaystyle \textstyle \Delta } is the epicentral distance (in kilometers unless otherwise specified).

The Lillie empirical formula:

{\displaystyle M_{\mathrm {L} }=\log _{10}A-2.48+2.76\log _{10}\Delta ,}

Where {\displaystyle A} is the amplitude (maximum ground displacement) of the P-wave, in micrometers, measured at 0.8 Hz.

For distances {\displaystyle D} less than 200 km,

{\displaystyle M_{\mathrm {L} }=\log _{10}A+1.6\log _{10}D-0.15,}

and for distances between 200 km and 600 km,

{\displaystyle M_{\mathrm {L} }=\log _{10}A+3.0\log _{10}D-3.38,}

where {\displaystyle A} is seismograph signal amplitude in mm and {\displaystyle D} is in km.

The Bisztricsany (1958) empirical formula for epicentral distances between 4˚ to 160˚:[30]

{\displaystyle M_{\mathrm {L} }=2.92+2.25\log _{10}(\tau )-0.001\Delta ^{\circ },}

Where {\displaystyle \tau } is the duration of the surface wave in seconds, and {\displaystyle \Delta } is in degrees. {\displaystyle M_{\mathrm {L} }} is mainly between 5 and 8.

The Tsumura empirical formula:[30]

{\displaystyle M_{\mathrm {L} }=-2.53+2.85\log _{10}(F-P)+0.0014\Delta ^{\circ }}

Where {\displaystyle F-P} is the total duration of oscillation in seconds. {\displaystyle M_{\mathrm {L} }} is mainly between 3 and 5.

The Tsuboi, University of Tokyo, empirical formula:

{\displaystyle M_{\mathrm {L} }=\log _{10}A+1.73\log _{10}\Delta -0.83}

Where {\displaystyle A} is the amplitude in micrometers.

# Puerto Rico Faces Hurricane Maria After Irma’s $1 Billion Damage • Governor warns flood-zone residents their lives are in danger • Island orders rationing of already scarce basic necessities Two weeks ago, Puerto Rico was spared a devastating hit when Hurricane Irma ripped up the Caribbean. This time, it may not be so lucky. The bankrupt island, already contending with the aftermath of a storm that left as much as$1 billion of damage and hundreds of thousands still without power, faces even more upheaval with Hurricane Maria set to hit as soon as Tuesday night. The government ordered rationing of basic necessities, including water and batteries, although those items were already gone from some San Juan store shelves as residents prepared for what could be the worst storm for the U.S. territory in decades.

“If you are in a flood zone or in a wood house, your life is in danger,” Governor Ricardo Rossello said during a press conference Monday in San Juan. “There has never been an event like this in our history in the last 100 years. Our call is for all citizens to move to a safe place.”

Puerto Rico is facing an active hurricane season with little financial ability to navigate a natural catastrophe. It filed for bankruptcy in May after years of economic decline and borrowing to fill budget gaps. A series of defaults have effectively left it unable to raise money in the capital markets. And its aging government-owned electric utility, the Electric Power Authority, is also operating under court protection from creditors. Puerto Rico’s emergency fund stood at about $32 million before Irma passed through. Prepa, the government-run utility, is still trying to restore power to hundreds of thousands of residents after its electrical infrastructure sustained as much as$400 million of the nearly \$1 billion of damage from Irma. It was already in need of upgrades because it relies on oil to produce most of its electricity and the median plant age is 44 years, more than twice the industry average.

“We will not have sustainable electric infrastructure in the near future,” Rossello said. “We will be bringing in crews from outside of Puerto Rico to attend to these measures.”

Rossello’s administration has opened nearly 500 shelters throughout the island and may set up more. Water, batteries, baby food and generators were already scarce in San Juan by Monday evening and motorists waited at least half an hour in line to buy gasoline. Officials estimate the last time the island withstood such a powerful storm was in 1928 with Hurricane San Felipe.

“No matter what happens here in the next 36 hours, Puerto Rico will survive, we will rebuild, we will recover and with your support, we will come out stronger than ever,” Rossello said in a statement Tuesday.

Maria’s threat hasn’t rattled the bond market, given that Puerto Rico has already defaulted and is seeking to have some of its debts discharged in bankruptcy. While its securities were actively traded as the storm gathered force, Puerto Rico debt maturing in 2035 changed hands Tuesday at an average price of 56.7 cents on the dollar, the lowest level since Sept. 1, data compiled by Bloomberg show.

The island is mostly insured by local firms, though has been seeking more international interest, according to a report published last year by the commonwealth’s commissioner of insurance’s office. Universal Insurance Group of Puerto Rico is the No. 1 provider of home coverage on the island, with almost 62 percent market share, according to data compiled by ratings firm A.M. Best. MAPFRE North America Group, ranked second with 22.5 percent of the market, is a unit of Spanish insurer Mapfre SA.

— With assistance by Sonali Basak

https://www.bloomberg.com/news/articles/2017-09-19/puerto-rico-faces-hurricane-maria-after-irma-s-1-billion-damage

# Saffir–Simpson scale

Saffir–Simpson scale
Category Wind speeds
Five ≥70 m/s, ≥137 knots, ≥157 mph,≥252 km/h
Four 58–70 m/s, 113–136 knots,130–156 mph, 209–251 km/h
Three 50–58 m/s, 96–112 knots,111–129 mph, 178–208 km/h
Two 43–49 m/s, 83–95 knots,96–110 mph, 154–177 km/h
One 33–42 m/s, 64–82 knots,74–95 mph, 119–153 km/h
Tropical storm 18–32 m/s, 34–63 knots,39–73 mph, 63–118 km/h ≤17 m/s, ≤33 knots, ≤38 mph,≤62 km/h

The Saffir–Simpson hurricane wind scale (SSHWS), formerly the Saffir–Simpson hurricane scale (SSHS), classifies hurricanes – Western Hemisphere tropical cyclones that exceed the intensities of tropical depressions and tropical storms – into five categories distinguished by the intensities of their sustained winds. To be classified as a hurricane, a tropical cyclone must have maximum sustained winds of at least 74 mph (33 m/s; 64 kn; 119 km/h) (Category 1). The highest classification in the scale, Category 5, contains storms with sustained winds exceeding 156 mph (70 m/s; 136 kn; 251 km/h).

The classifications can provide some indication of the potential damage and flooding a hurricane will cause upon landfall.

Officially, the Saffir–Simpson hurricane wind scale is used only to describe hurricanes forming in the Atlantic Ocean and northern Pacific Ocean east of the International Date Line. Other areas use different scales to label these storms, which are called “cyclones” or “typhoons“, depending on the area.

There is some criticism of the SSHS for not taking rain, storm surge, and other important factors into consideration, but SSHS defenders say that part of the goal of SSHS is to be straightforward and simple to understand.

The scale was developed in 1971 by civil engineer Herbert Saffir and meteorologist Robert Simpson, who at the time was director of the U.S. National Hurricane Center (NHC).[1] The scale was introduced to the general public in 1973,[2] and saw widespread use after Neil Frank replaced Simpson at the helm of the NHC in 1974.[3]

The initial scale was developed by Saffir, a structural engineer, who in 1969 went on commission for the United Nations to study low-cost housing in hurricane-prone areas.[4] While performing the study, Saffir realized there was no simple scale for describing the likely effects of a hurricane. Mirroring the utility of the Richter magnitude scale in describing earthquakes, he devised a 1–5 scale based on wind speed that showed expected damage to structures. Saffir gave the scale to the NHC, and Simpson added the effects of storm surgeand flooding.

In 2009, the NHC made moves to eliminate pressure and storm surge ranges from the categories, transforming it into a pure wind scale, called the Saffir–Simpson Hurricane Wind Scale (Experimental) [SSHWS].[5] The new scale became operational on May 15, 2010.[6]The scale excludes flood ranges, storm surge estimations, rainfall, and location, which means a Category 2 hurricane which hits a major city will likely do far more cumulative damage than a Category 5 hurricane that hits a rural area.[7] The agency cited various hurricanes as reasons for removing the “scientifically inaccurate” information, including Hurricane Katrina (2005) and Hurricane Ike (2008), which both had stronger than estimated storm surges, and Hurricane Charley (2004), which had weaker than estimated storm surge.[8] Since removed from the Saffir–Simpson hurricane wind scale, storm surge predicting and modeling is now handled with the use of a computerized numerical model developed by the National Weather Service called “Sea, Lake, and Overland Surge from Hurricanes” (SLOSH).

In 2012, the NHC expanded the windspeed range for Category 4 by 1 mph in both directions, to 130–156 mph, with corresponding changes in the other units (113–136 kn, 209–251 km/h), instead of 131–155 mph (114–135 kn, 210–249 km/h). The NHC and the Central Pacific Hurricane Center assign tropical cyclone intensities in 5 knot increments, and then convert to mph and km/h with a similar rounding for other reports. So an intensity of 115 knots is rated Category 4, but the conversion to miles per hour (132.3 mph) would round down to 130 mph, making it appear to be a Category 3 storm. Likewise, an intensity of 135 knots (~155 mph, and thus Category 4) is 250.02 km/h, which according to the definition used before the change would be Category 5. To resolve these issues, the NHC had been obliged to incorrectly report storms with wind speeds of 115 kn as 135 mph, and 135 kn as 245 km/h. The change in definition allows storms of 115 kn to be correctly rounded down to 130 mph, and storms of 135 kn to be correctly reported as 250 km/h, and still qualify as Category 4. Since the NHC had previously rounded incorrectly to keep storms in Category 4 in each unit of measure, the change does not affect the classification of storms from previous years.[5] The new scale became operational on May 15, 2012.[9]

## Categories

The scale separates hurricanes into five different categories based on wind. The U.S. National Hurricane Center classifies hurricanes of Category 3 and above as major hurricanes, and the Joint Typhoon Warning Center classifies typhoons of 150 mph or greater (strong Category 4 and Category 5) as super typhoons (although all tropical cyclones can be very dangerous). Most weather agencies use the definition for sustained winds recommended by the World Meteorological Organization (WMO), which specifies measuring winds at a height of 33 ft (10.1 m) for 10 minutes, and then taking the average. By contrast, the U.S. National Weather ServiceCentral Pacific Hurricane Center and the Joint Typhoon Warning Center define sustained winds as average winds over a period of one minute, measured at the same 33 ft (10.1 m) height,[10][11] and that is the definition used for this scale. Intensity of example hurricanes is from both the time of landfall and the maximum intensity.

The scale is roughly logarithmic in wind speed, and the top wind speed for Category “c” (c=1 to 4, as there is no upper limit for category 5) can be expressed as 83×10^(c/15) miles per hour rounded to the nearest multiple of 5 – except that after the change mentioned above, Category 4 is now widened by 1 mph in each direction.

The five categories are, in order of increasing intensity:[12]

### Category 1

Category 1
Sustained winds Most Recent
33–42 m/s
64–82 kn
119–153 km/h
74–95 mph
Hurricane Max shortly before landfall in Mexico in September 2017.

Very dangerous winds will produce some damage

Category 1 storms usually cause no significant structural damage to most well-constructed permanent structures; however, they can topple unanchored mobile homes, as well as uproot or snap weak trees. Poorly attached roof shingles or tiles can blow off. Coastal flooding and pier damage are often associated with Category 1 storms. Power outages are typically widespread to extensive, sometimes lasting several days. Even though it is the least intense type of hurricane, the storm can still produce widespread damage and can be a life-threatening storm.[5]

Hurricanes that peaked at Category 1 intensity, and made landfall at that intensity include: Flossy (1956), Gladys (1968), Agnes (1972), Juan (1985), Ismael (1995), Claudette (2003), Gaston (2004), Stan (2005), Humberto (2007), Isaac (2012), Manuel (2013), Earl (2016), Hermine (2016), Newton (2016), Franklin (2017), and Max (2017).

### Category 2

Category 2
Sustained winds Most Recent
43–49 m/s
83–95 kn
154–177 km/h
96–110 mph

Arthur in 2014 approaching North Carolina.

Extremely dangerous winds will cause extensive damage

Storms of Category 2 intensity often damage roofing material (sometimes exposing the roof) and inflict damage upon poorly constructed doors and windows. Poorly constructed signs and piers can receive considerable damage and many trees are uprooted or snapped. Mobile homes, whether anchored or not, are typically damaged and sometimes destroyed, and many manufactured homes also suffer structural damage. Small craft in unprotected anchorages may break their moorings. Extensive to near-total power outages and scattered loss of potable water are likely, possibly lasting many days.[5]

Hurricanes that peaked at Category 2 intensity, and made landfall at that intensity include: Able (1952), Alice (1954), Fifi (1974), Diana (1990), Calvin (1993), Gert (1993), Rosa (1994), Erin (1995), Alma (1996), Juan (2003), Alex (2010), Richard (2010), Tomas (2010), Carlotta (2012), Ernesto (2012), and Arthur (2014).

### Category 3

Category 3
Sustained winds Most Recent
50–58 m/s
96–112 kn
178–208 km/h
111–129 mph

Otto near its landfall on Nicaragua.

Devastating damage will occur

Tropical cyclones of Category 3 and higher are described as major hurricanes in the Atlantic or Eastern Pacific basins. These storms can cause some structural damage to small residences and utility buildings, particularly those of wood frame or manufactured materials with minor curtain wall failures. Buildings that lack a solid foundation, such as mobile homes, are usually destroyed, and gable-end roofs are peeled off. Manufactured homes usually sustain severe and irreparable damage. Flooding near the coast destroys smaller structures, while larger structures are struck by floating debris. A large number of trees are uprooted or snapped, isolating many areas. Additionally, terrain may be flooded well inland. Near-total to total power loss is likely for up to several weeks and water will likely also be lost or contaminated.[5]

Hurricanes that peaked at Category 3 intensity, and made landfall at that intensity include: Easy (1950), Carol (1954), Hilda (1955), Celia (1970), Ella (1970), Eloise (1975), Olivia (1975), Alicia (1983), Elena (1985), Roxanne (1995), Fran (1996), Isidore (2002), Lane (2006), Karl (2010), Sandy (2012) and Otto (2016).

### Category 4

Category 4
Sustained winds Most Recent
58–70 m/s
113–136 kn
209–251 km/h
130–156 mph

Harvey in August 2017 shortly before its Texaslandfall.

Catastrophic damage will occur

Category 4 hurricanes tend to produce more extensive curtainwall failures, with some complete structural failure on small residences. Heavy, irreparable damage and near complete destruction of gas station canopies and other wide span overhang type structures are common. Mobile and manufactured homes are often flattened. Most trees, except for the heartiest, are uprooted or snapped, isolating many areas. These storms cause extensive beach erosion, while terrain may be flooded far inland. Total and long-lived electrical and water losses are to be expected, possibly for many weeks.[5]

The 1900 Galveston hurricane, the deadliest natural disaster to hit the United States, peaked at an intensity that corresponds to a modern-day Category 4 storm. Other examples of storms that peaked at Category 4 intensity, and made landfall at that intensity include: Hazel (1954), Gracie (1959), Flora (1963), Cleo (1964), Betsy (1965), Frederic (1979), Joan (1988), Iniki (1992), Luis (1995), Iris (2001), Charley (2004), Dennis(2005), Gustav (2008), Ike (2008), Joaquin (2015), and Harvey (2017).

### Category 5

Category 5
Sustained winds Most Recent
≥ 70 m/s
≥ 137 kn
≥ 252 km/h
≥ 157 mph
Maria in September 2017 approaching landfall on Dominica.

Cataclysmic damage will occur

Category 5 is the highest category of the Saffir–Simpson scale. These storms cause complete roof failure on many residences and industrial buildings, and some complete building failures with small utility buildings blown over or away. Collapse of many wide-span roofs and walls, especially those with no interior supports, is common. Very heavy and irreparable damage to many wood frame structures and total destruction to mobile/manufactured homes is prevalent. Only a few types of structures are capable of surviving intact, and only if located at least 3 to 5 miles (5 to 8 km) inland. They include office, condominium and apartment buildings and hotels that are of solid concrete or steel frame construction, public multi-story concrete parking garages, and residences that are made of either reinforced brick or concrete/cement block and have hipped roofs with slopes of no less than 35 degrees from horizontal and no overhangs of any kind, and if the windows are either made of hurricane-resistant safety glass or covered with shutters. Unless all of these requirements are met, the absolute destruction of a structure is certain.[5]

The storm’s flooding causes major damage to the lower floors of all structures near the shoreline, and many coastal structures can be completely flattened or washed away by the storm surge. Virtually all trees are uprooted or snapped and some may be debarked, isolating most affected communities. Massive evacuation of residential areas may be required if the hurricane threatens populated areas. Total and extremely long-lived power outages and water losses are to be expected, possibly for up to several months.[5]

Historical examples of storms that made landfall at Category 5 status include: “Cuba” (1924), “Okeechobee” (1928), “Bahamas” (1932), “Cuba–Brownsville” (1933), “Labor Day” (1935), Janet (1955), Camille (1969), Edith (1971), Anita (1977), David (1979), Gilbert (1988), Andrew (1992), Dean (2007), Felix (2007), Irma (2017),[13] and Maria (2017).[14] No Category 5 hurricane is known to have made landfall at that strength in the eastern Pacific basin.

## Criticism

Some scientists, including Kerry Emanuel and Lakshmi Kantha, have criticized the scale as being simplistic, indicating that the scale takes into account neither the physical size of a storm nor the amount of precipitation it produces.[7] Additionally, they and others point out that the Saffir–Simpson scale, unlike the Richter scale used to measure earthquakes, is not continuous, and is quantized into a small number of categories. Proposed replacement classifications include the Hurricane Intensity Index, which is based on the dynamic pressure caused by a storm’s winds, and the Hurricane Hazard Index, which bases itself on surface wind speeds, the radius of maximum winds of the storm, and its translational velocity.[15][16] Both of these scales are continuous, akin to the Richter scale;[17] however, neither of these scales have been used by officials.

### “Category 6”

After the series of powerful storm systems of the 2005 Atlantic hurricane season, a few newspaper columnists and scientists brought up the suggestion of introducing Category 6, and they have suggested pegging Category 6 to storms with winds greater than 174 or 180 mph (78 or 80 m/s; 151 or 156 kn; 280 or 290 km/h).[7][18] Only a few storms of this intensity have been recorded. Of the 33 hurricanes currently considered to have attained Category 5 status in the Atlantic, 17 had wind speeds at 175 mph (78 m/s; 152 kn; 282 km/h) or greater and only seven had wind speeds at 180 mph (80 m/s; 160 kn; 290 km/h) or greater (the 1935 Labor Day hurricaneAllenGilbertMitchRitaWilma, and Irma). Of the 15 hurricanes currently considered to have attained Category 5 status in the eastern Pacific, only six had wind speeds at 175 mph (78 m/s; 152 kn; 282 km/h) or greater (PatsyJohnLindaRick, and Patricia), and only three had wind speeds at 180 mph (80 m/s; 160 kn; 290 km/h) or greater (Linda, Rick, and Patricia). However, most storms which would be eligible for this category were typhoons in the western Pacific, most notably Typhoon Tip in 1979 with sustained winds of 190 mph (310 km/h) and typhoons Haiyan and Meranti in 2013 and 2016, respectively, with sustained winds of 195 mph (314 km/h).[19]

According to Robert Simpson, there are no reasons for a Category 6 on the Saffir–Simpson Scale because it is designed to measure the potential damage of a hurricane to human-made structures. Simpson stated that “…when you get up into winds in excess of 155 mph (249 km/h) you have enough damage if that extreme wind sustains itself for as much as six seconds on a building it’s going to cause rupturing damages that are serious no matter how well it’s engineered.”[3] Despite his statements, the counties of Broward and Miami-Dade in Florida have building codes which require critical infrastructure buildings to be able to withstand hurricane winds of 156 and up,[20] which contradicts Mr. Simpson’s assessment of building strength. Absent a “Category 6”, governments have no guidance as to where “up” should end.

## References

1. Jump up^ Williams, Jack (May 17, 2005). “Hurricane scale invented to communicate storm danger”USA Today. Retrieved February 25, 2007.
2. Jump up^ Staff writer (May 9, 1973). “’73, Hurricanes to be Graded”. Associated Press. Archived from the original on May 19, 2016. Retrieved December 8, 2007.
3.  Debi Iacovelli (July 2001). “The Saffir/Simpson Hurricane Scale: An Interview with Dr. Robert Simpson”Sun-Sentinel. Fort Lauderdale, Fla. Retrieved September 10, 2006.
4. Jump up^ Press Writer (August 23, 2001). “Hurricanes shaped life of scale inventor”. Retrieved March 20, 2016.[dead link]
5.  The Saffir–Simpson Hurricane Wind Scale National Hurricane Center. Accessed 2009-05-15.
6. Jump up^ National Hurricane Operations Plan Archived July 8, 2011, at the Wayback Machine., NOAA. Accessed July 3, 2010.
7.  Ker Than (October 20, 2005). “Wilma’s Rage Suggests New Hurricane Categories Needed”LiveScience. Retrieved October 20, 2005.
8. Jump up^ “Experimental Saffir–Simpson Hurricane Wind Scale” (PDF). National Hurricane Center. 2009.
9. Jump up^ Public Information StatementNOAA. Accessed March 9, 2012.
10. Jump up^ Tropical Cyclone Weather Services Program (June 1, 2006). “Tropical cyclone definitions” (PDF). National Weather Service. Retrieved November 30, 2006.
11. Jump up^ Federal Emergency Management Agency (2004). “Hurricane Glossary of Terms”. Archived from the original on December 14, 2005. Retrieved March 24, 2006. Accessed through the Wayback Machine.
12. Jump up^ “Name That Hurricane: Famous Examples of the 5 Hurricane Categories”Live Science. Retrieved 2017-09-11.
13. Jump up^ “Famous Hurricanes of the 20th and 21st Century in the United States” (PDF). http://www.weather.gov/crh/.
14. Jump up^ Brown, Daniel. “Hurricane Maria Tropical Cyclone Update”. National Hurricane Center. Retrieved 19 September 2017.
15. Jump up^ Kantha, L. (January 2006). “Time to Replace the Saffir–Simpson Hurricane Scale?” (PDF). Eos87 (1): 3, 6. Bibcode:2006EOSTr..87….3Kdoi:10.1029/2006eo010003. Retrieved December 8, 2007.
16. Jump up^ Kantha, Lakshmi (February 2008). “Tropical Cyclone Destructive Potential by Integrated Kinetic Energy” (PDF). Bulletin of the American Meteorological Society. Boston: American Meteorological Society89 (2): 219–221. Bibcode:2008BAMS…89..219Kdoi:10.1175/BAMS-89-2-219.
17. Jump up^ Benfield Hazard Research Centre (2006). “Atmospheric Hazards”Hazard & Risk Science Review 2006University College London. Retrieved December 8, 2007.
18. Jump up^ Bill Blakemore (May 21, 2006). “Category 6 Hurricanes? They’ve Happened: Global Warming Winds Up Hurricane Scientists as NOAA Issues Its Atlantic Hurricane Predictions for Summer 2006”ABC News. Retrieved September 10, 2006.
19. Jump up^ Debi Iacovelli and Tim Vasquez (1998). “Supertyphoon Tip: Shattering all records” (PDF). Monthly Weather Log. National Oceanic and Atmospheric Administration. Retrieved September 19, 2010.
20. Jump up^ Jennifer Kay (September 2017). “Irma could test strength of Florida’s strict building codes”The_Washington_Post. Washington, DC. Retrieved September 16, 2017.