New research from North Carolina State University finds that major volcanic activity on the planet Mercury most likely ended about 3.5 billion years ago.

These findings add insight into the geological evolution of Mercury in particular, and what happens when rocky planets cool and contract in general.

There are two types of volcanic activity: effusive and explosive.

Explosive volcanism is often a violent event that results in large ash and debris eruptions, such as the Mount Saint Helens eruption in 1980.

Effusive volcanism refers to widespread lava flows that slowly pour out over the landscape – believed to be a key process by which planets form their crusts.

Determining the ages of effusive volcanic deposits can give researchers a handle on a planet’s geological history.

For example, effusive volcanism was active a few hundred million years ago on Venus, a few million years ago on Mars, and it still takes place on Earth today.

Until now, the duration of effusive volcanic activity on Mercury, made of the same materials as these other planets, had not been known.

NC State assistant professor and planetary geologist Paul Byrne and colleagues determined when the bulk of Mercury’s crust-forming volcanism ended by using photographs of the surface imaged by NASA’s MESSENGER mission.

Because there are no physical samples from the planet that could be used for radiometric dating, the researchers used crater size–frequency analysis, in which the number and size of craters on the planet’s surface are placed into established mathematical models, to calculate absolute ages for effusive volcanic deposits on Mercury.

According to their results, major volcanism on Mercury stopped at around 3.5 billion years ago, in stark contrast to the volcanic ages found for Venus, Mars and Earth.

“There is a huge geological difference between Mercury and Earth, Mars or Venus,” Byrne said. “Mercury has a much smaller mantle, where radioactive decay produces heat, than those other planets, and so it lost its heat much earlier. As a result, Mercury began to contract, and the crust essentially sealed off any conduits by which magma could reach the surface.

“These new results validate 40-year-old predictions about global cooling and contraction shutting off volcanism,” Byrne continued. “Now that we can account for observations of the volcanic and tectonic properties of Mercury, we have a consistent story for its geological formation and evolution, as well as new insight into what happens when planetary bodies cool and contract.”

The research appears in Geophysical Research Letters, with co-authors from the Carnegie Institution of Washington, Mount Holyoke College, the University of Georgia, Southwest Research Institute and Brown University. The MESSENGER mission provided substantial funding for this work.

NORTHERN CALIFORNIA – California Department of Public Health Director and State Health Officer Dr. Karen Smith announced the first confirmed death in California this year due to West Nile virus.

The person who died was a senior citizen in Sacramento County, Smith said.
 
“West Nile virus can cause a deadly infection in humans, and the elderly are particularly susceptible, as this unfortunate fatality illustrates,” said Dr. Smith. “West Nile virus activity in the state is increasing, so I urge Californians to take every possible precaution to protect themselves against mosquito bites.”
 
CDPH has reported 10 human cases of WNV from eight California counties this year. In addition, 764 dead birds from 26 counties have tested positive for WNV in 2016 and 1,487 mosquito samples from 30 counties have also tested positive for WNV this year.
 
The number of WNV positive dead birds and mosquito samples exceeds the numbers at this same time last year and are above the state’s most recent five-year average.

In Lake County, there have been no human cases so far this year, according to local and state officials.

Lake County has had several human cases over the past decade. While the county had no human cases from 2007 to 2011, and no cases in 2013, it had one case each in 2012 and 2014, and two cases in 2015, state records showed.

The first case of West Nile virus in a bird – a domestic turkey from north Lakeport – was confirmed July 1, as Lake County News has reported.

Since then, two more dead birds – including a great blue heron – in Lake County have been confirmed to have the virus, along with a total of 13 mosquito samples, according to the case count.

State officials said the virus is now active in 34 of California's 58 counties, compared to 37 counties with the virus at this time last year.
 
West Nile virus is influenced by many factors, including climate, the number and types of birds and mosquitoes in an area and the level of WNV immunity in birds. West Nile is transmitted to humans and animals by the bite of an infected mosquito.

The risk of serious illness to most people is low. However, some individuals – less than 1 percent – can develop serious neurologic illnesses such as encephalitis or meningitis.
 
People 50 years of age and older and individuals with diabetes or hypertension have a higher chance of getting sick and are more likely to develop complications.
 
CDPH recommends that individuals protect against mosquito bites and WNV by practicing the “Three Ds”:
 
– DEET: Apply insect repellent containing DEET, picaradin, oil of lemon eucalyptus or IR3535 according to label instructions. Repellents keep the mosquitoes from biting you. Insect repellents should not be used on children under two months of age.

– DAWN AND DUSK: Mosquitoes usually bite in the early morning and evening so it is important to wear proper clothing and repellent if outside during these times. Make sure that your doors and windows have tight-fitting screens to keep out mosquitoes. Repair or replace screens that have tears or holes.

– DRAIN: Mosquitoes lay their eggs on standing water. Eliminate all sources of standing water on your property, by emptying flower pots, old car tires, buckets, and other containers. If you know of a swimming pool that is not being properly maintained, please contact your local mosquito and vector control agency.
 
California’s West Nile virus Web site includes the latest information on WNV activity in the state.

Californians are encouraged to report dead birds on the Web site or by calling toll-free 1-877-WNV-BIRD (968-2473).

CLEARLAKE, Calif. – A Clearlake man was arrested last week after he was found in possession of several ounces of methamphetamine while driving a motorcycle on a suspended license.

Billy Wayne Stimmel, 43, was arrested on the evening of July 30, according to a report from Sgt. Tim Hobbs of the Clearlake Police Department.

Hobbs said that at 8:10 p.m. that day Officer Mark Harden observed Stimmel riding a motorcycle on Austin Drive. A check via dispatch revealed Stimmel had a suspended driver's license. 

Harden attempted to catch up with the motorcycle and did so when it pulled over on Saroni Parkway west of Old Highway 53, Hobbs said.

Hobbs said Harden contacted Stimmel and arrested him for driving with a suspended driver’s license. 

During a subsequent search incident to Stimmel's arrest, Harden located approximately 4 ounces of methamphetamine in a pocket of Stimmel’s shorts, said Hobbs, which led to Stimmel being additionally charged with possession of methamphetamine for sale.

Stimmel was later booked into the Lake County Jail, with bail set at $15,000. He has since posted bail and been released, according to jail records.

Anyone with information regarding the unlawful possession or sales of controlled substances can contact the Clearlake Police Department at 707-994-8251. Callers may remain anonymous.

LAKE COUNTY, Calif. – The Lake County Sheriff’s Office/County Office of Emergency Services said it still has a limited number of weather radios available to Valley fire area residents.

Undersheriff Chris Macedo said there are approximately 20 of the Midland WR120 Desktop Weather Alert Radios left. 

A total of 333 of the radios has been purchased earlier this year thanks to a $10,000 grant to the Lake County Sheriff’s Office of Emergency Services from State Farm, as Lake County News has reported.

If a resident who lives in the footprint of the Valley fire would like to receive a NOAA Weather Radio, Macedo said they may pick one up at the Lake County Sheriff’s Office, located at 1220 Martin St. in Lakeport.

In order to receive one of the radios, individuals must meet the criteria below and bring proof of residency to the sheriff’s office. Only one radio per residence will be given away. These radios are free of charge. 

The following criteria were established in order to be eligible for the radios:

– Must currently be residing in the footprint of the Valley fire.
– Must provide proof of residency by showing either a valid California Driver’s License or California Identification Card that lists the physical address or utility bill such as a water, phone cable, PG&E that has the service (home) address listed.
– Post office box addresses are insufficient and will not be accepted as proof of residency.

If homeowners or residents are interested in more information about the NOAA Weather Radios, they can visit http://www.nws.noaa.gov/nwr/info/nwrrcvr.html#buy .

The Air Operations Program of the California Highway Patrol recently became one of 10 accredited air operations programs in the United States.
 
The Public Safety Aviation Accreditation Commission, or PSAAC, awarded the accreditation at the Airborne Law Enforcement Association Expo held in Savannah, Ga., July 18 to 23.

The CHP is the largest state agency to complete the PSAAC accreditation process.
 
“I am extremely proud of the men and women in our Air Operations Program and the service they provide on a daily basis,” CHP Commissioner Joe Farrow said. “Receiving PSAAC accreditation validates our commitment to excellence and demonstrates the CHP’s desire to continually look for opportunities for self-improvement.”
 
The award concludes a three-year pursuit for recognition of implementing industry standards intended to promote best practices throughout the airborne law enforcement community.

By voluntarily complying with PSAAC standards, the CHP is recognized for its safe, effective and efficient aviation operations.
 
The CHP Air Operations Program began in the late 1960s and consists of 15 airplanes and 15 helicopters.

The air fleet assists CHP field operations and allied agencies across the state for emergency response, homeland security missions, patrol of rural roadways, speed enforcement, special events and transportation.

More than 170 CHP pilots and flight officers in eight air units throughout the state provide service to the public and allied agencies.

In 2015, Air Operations flew 8,633 search missions, 396 rescue missions and saved 14 lives.
 
The accreditation process includes five phases: enrollment, self-assessment, unit assessment, commission review, and maintaining compliance and re-accreditation.

A team of PSAAC assessors visited the CHP in October 2015 and examined all aspects of the CHP Air Operations Program, including administrative, operational, safety, training and maintenance standards.

Because accreditation is an ongoing process, the department must continually prove compliance with PSAAC standards and submit to periodic on-site assessments.

The California Department of Public Health (CDPH) reported that two infants with Zika-related microcephaly have been born in California to women who had Zika virus infections during pregnancy after spending time in a country where the virus is endemic.

While mosquitoes that can carry the virus have been found in 12 California counties, there is no evidence these mosquitoes are transmitting Zika in the state at this time.

Lake County is not among the counties where the mosquitoes have been found, according to CDPH monitoring records. The 12 counties are Alameda, Fresno, Imperial, Kern, Los Angeles, Madera, Orange, Riverside, San Bernardino, San Diego, San Mateo and Tulare.
 
“This is a sobering reminder for Californians that Zika can cause serious harm to a developing fetus,” said CDPH Director and State Health Officer Dr. Karen Smith. “We join the Centers for Disease Control and Prevention in urging pregnant women to avoid travel to areas with known Zika transmission. Pregnant women who must travel to one of these areas should strictly follow steps to prevent mosquito bites and speak with a health care provider upon return.”
 
Smith added, “Zika virus can also be transmitted to sexual partners by both males and females. Both men and women of childbearing age should take precautions if they have recently traveled, or plan to travel, to a location where Zika is spreading.”
 
A team of experts across several disciplines at CDPH is working closely with local public health departments, vector control agencies and the medical community to ensure that California is responding aggressively and appropriately to the emerging threat of Zika virus.

CDPH is actively monitoring all pregnant women with Zika infection in California. The Department is also collaborating with local health departments to provide assistance to families with infants born with Zika-related birth defects to ensure they receive appropriate medical care. Infants born to mothers with confirmed infections will be monitored for one year.
 
As of July 29, CDPH has confirmed 114 travel-associated Zika virus infections in 22 counties. A total of 21 infections have been confirmed in pregnant women. This information is updated every Friday on the CDPH Zika Web site.

CDPH records show that as of July 29, infections have been confirmed in the neighboring counties of Napa, Sonoma and Yolo, as well as Alameda, Contra Costa, Fresno, Los Angeles, Marin, Merced, Monterey, Orange, Riverside, San Bernardino, San Diego, San Francisco, San Joaquin, San Mateo, Santa Clara, Solano, Stanislaus, Tulare and Yuba.
 
While Zika infection is often asymptomatic, those who do have symptoms report fever, rash, joint pain and conjunctivitis (red eyes).

The illness is usually mild with symptoms lasting for several days to a week after being bitten by an infected mosquito.

There is currently no vaccine or treatment for Zika other than supportive care, rest, fluids and fever relief.

People traveling to areas with known Zika transmission should take steps to avoid mosquito bites:
 
· Use insect repellents containing DEET, picaridin, IR3535, oil of lemon eucalyptus or para-menthane-diol for long-lasting protection. If using sunscreen and insect repellent, apply sunscreen first and then the repellent. Pregnant women and women who are breastfeeding should choose an EPA-registered insect repellent and use it according to the product label. Do not use insect repellent on infants less than two months of age.

· Wear long-sleeved shirts and long pants.

· Use air conditioning or window and door screens to keep mosquitoes outside. If mosquitoes may come indoors, sleep under a bed net.

· Reduce the number of mosquitoes outside by emptying standing water from containers, such as flower pots and buckets.

Sexually active adults who travel to areas with Zika transmission should use condoms or other barriers in order to avoid getting or passing Zika during sex. Couples planning pregnancy should speak with a health care provider about a safe time to wait before trying to get pregnant.

CDPH provides Zika-related pregnancy outcome data to the U.S. Zika Pregnancy Registry maintained by the Centers for Disease Control, which is collecting this information to better understand the risks posed by Zika infection during pregnancy.
 
In order to protect privacy, CDPH is not releasing additional details or the locations of the mothers and children. Infants born with birth defects, including microcephaly, as a result of maternal Zika infection do not pose a public health risk to their communities.
 
For more information about Zika, visit the CDPH Zika Web site, which includes resources on Zika and travel, pregnancy, sex and bite prevention.